No one has described the so-called sociopolitical system and its dynamic (how it reproduces). What we have speculative accounts, ad hoc in nature. Let's look at endogamy.

"A caste is an endogamous group, or collection of endogamous groups, bearing a common name, membership of which is hereditary, arising from birth alone; imposing on its members certain restrictions in the matter of social intercourse; either (i) following a common traditional occupation, or (ii) claiming a common origin, or (iii) both following such occupation and claiming such origin; and generally regarded as forming a single homogenous community" (p.5 of Blunt's The caste system of Northern India)

"The endogamy of a subcaste is not as rigid as that of a caste. A marriage between (say) a Brahman bridegroom and a Rajput bride is unthinkable, but intermarriages have occurred between subcastes of the same caste with no worse consequences than a purificatory sacrifice; and if circumstances make it desirable, such as lack of women, subcaste endogamy is abandoned. Even in the Brahman caste this has occurred. Subcaste endogamy is muta- ble; sometimes a subcaste which is endogamous in one place is not so in another. A trifling quarrel will drive two groups that formerly intermarried to endogamy: the removal of the cause of offense removes the restriction. But the most potent of all objections is the fact that endogamous subcastes are not regarded by their own members or by the rest of Hindu society as castes. To call such groups castes is to treat them as being what no Hindu would admit them to be. An investigator is not at liberty to manipulate his material so as to make it fit his theories." ( ibid, 6-7)

From a field study from Karnataka:
"[O]ut of the 600 Panchayat members, majority of them did not endorse strict endogamy, commensality, untouchability. Nonetheless these respondents, did express their willingness to continue their jati tradition. This makes sense only when they think that these are not constituent properties of the jati traditions. Otherwise how can they disagree with the so called constituent properties of the jati and yet are willing to continue with their affiliation to their jati. This either indicates that none of the so-called characteristic features of the caste system are valid for these jatis or that the jati structure can include or exclude anything and still survive.

Those who consider the jatis as the referential points of the term caste, hold endogamy to be the most fundamental to the caste difference. However the Swamis of some of these jatis advocate for inter jati marriages for various reasons, like for survival of the jati against shortage of brides, or to unite different jatis belonging to the same cluster like Lingayat, Brahmana.. Though they have their own preferences of jatis to be accepted for inter marriage, this at least indicates that endogamy is not a constituent property of the jati units The Havyak Brahmins preferred inter-jati marriage as a means of saving their jati from the crisis of brides. In the case of Lingayat swamis, inter-jati marriage is viewed as a way to unite the Lingayats."

The real biggest problem is: what is a caste? For instance, in the states of Andhra Pradesh/Telangana, after the internet revolution, I have seen people talking about "reddy society". When I asked these society members, what makes some Subba Reddy from a village A, Kurnool District, another Ram Reddy from a village B, Nalgonda District, as belong to the reddy-caste? Their simple answer: because we are all reddy-s, we have that 'reddy' tag in our names. This is a circular explanation. If one goes back 40 years ago, we heard different kinds of reddy-s: pakanati, pedakanti, neravadi, panta, etc. People from each of these (pakanati, pedakanti, ...) didn't marry from other groups. Is there a super-caste called 'reddy', whose sub-castes are pakanati, pedakanti, neravadi, panta, etc? Or pakanati, pedakanti, neravadi, panta, etc are different castes? No answer.

In fact, the name 'pakanati' is related to a geographical area called 'paaka-naadu'. Even some other 'sub'-castes (not reddy-s) have paaka-naadu in their group. The whole debate is mired in this. British tried to classify and gave up on this project.

Let me cite another way of describing this:

'While emphasizing that I do not attack and much less defend the caste system in what follows, let us look at the existing descriptions and their consequences.

(a) Caste is an antiquated social system that arose in the dim past of India. If this is true, it has survived many challenges – the onslaught of Buddhism and the Bhakti movements, the Islamic and British colonization, Indian independence, world capitalism – and might even survive ‘globalization’. It follows, then, that the caste system is a very stable social organization.

(b) There exists no centralized authority to enforce the caste system across the length and breadth of India. In that case, it is an autonomous and decentralized organization.

(c) All kinds of social and political regulations, whether by the British or by the Indians, have not been able to eradicate this system. If true, it means that the caste system is a self-reproducing social structure.

(d) Caste system exists among the Hindus, the Sikhs, the Jains, the Christians, the Muslims… It has also existed under different environments. This means that this system adapts itself to the environments it finds itself in.

(e) Because new castes have come and gone over the centuries, this system must also be dynamic.

(f) Since caste system is present in different political organizations and survives under different political regimes, it is also neutral with respect to political ideologies.

Even though more can be said, this is enough for us. A simple redescription of what we think we know about the caste system tells us that it is an autonomous, decentralized, stable, adaptive, dynamic, self-reproducing social organization. It is also neutral with respect to political, religious and economic doctrines and environments. If indeed such a system ever existed, would it also not have been the most ideal form of social organization one could ever think of?
How can we try to understand this odd state of affairs? The question of the immorality of the caste system became immensely important after the British came to India. Consequently, there are two interesting possibilities to choose from: one, Indians did not criticize the caste system (before the British came to India) because Indians are immoral; two, the Europeans ‘discovered’ something that simply does not exist in India, viz. the social organization that the caste system is supposed to be.

The reason why I have spent time on this issue is to signal in the direction of a problem, which has very far-reaching consequences. If what Europe knows about India resembles what it claims to know about the caste system, what exactly does Europe know about India or her culture? Not very much, I am afraid.'[1]

[1] https://www.outlookindia.com/website/story/what-can-india-of...