[Redmi 9A ROMs, Kernels, Recoveries, & Other Develo] jdd1996:
Bare with me for 5-12 mins. You or may not agree with me, but it works like this in many ocassions.

Let's say i have a AMD A-5200 CPU , which is a cpu from 2013.

OR - Let's say i have a Intel Pentium 4 P4 - 2.0Ghz from the year 2008

OK? ok the example starts with 2 weak cpu's from ANCIENT TIMES now...

What OS can/would you install in those CPU's?

A Pentium 4 2.0 has 400 MHz. EACH 100mhz translates more or less to 5-15 khz of electrical power the cpu needs to process the information, the data.

Since its so weak, in windows10 or 11 when you open microsoft word 2020 or open office, it will LAG! because the overlay/background OS' is already consuming around 200ghz, all those 400 mhz of cpu power

(Animations, and Cortana, and simply the theme of the wallpaper, and the Registry, and Services, AND even USB peripherical drivers ARE ALL CONSUMING CPU POWER AT ONCE, and at high demands because the OS' Requests it with its kernel )

Since the core memory is so weak! you will most likely be installing windows xp or windows 7 if you're lucky !

BUT if you install windows 11 or 10, you will face unconsistent algorythmical graphic/memory processes

(This is what we call lag) core processing and clock problems, " MEMORY LEAKING problems " or over saturations of the system.

A CPU CONTAINS something called MMU's Memory management unit's, well they start to become obsolete unless you reball and resolder the cpu,

SAME applies if i tried to install LATEST FEDORA OR ARCH LINUX OS's , right? WHY would there be problems?

Because kernels are being update to be version 6.2 today, and that demands a constant clock and processing.

For the AMD A6-5200, Linux and windows 7 would be good options, but for the Pentium 4 2.0ghz of 2008 only windows 7 and Linux with low kernel version of 5 or 5.2 are acceptable.

So these techs at xiomi think similarly, on top of that the Storage of the OS increases, the RAM demand, CPU demand increases with each version, so when you boot your game (mostly the demanding apps) when you boot your designer pen drawing app, IT WILL LAG , perhaps not noticeably for the user in android 12 or 13, BUT AS VERSIONS WILL CONTINUE TO PASS, in Android 13-14 , we will see how this Xiomi Redmi 9A , ITS PROCESSOR and its weak 2gb will not be enough to process/render the datas and assets of the newest OS's

hahaha all that to say, sorry i got inspired " They need to optimize the OS's in the future maybe then we may be able to install newer OS's on older phones " Its like putting android 12 on an Android 8.1 Oreo phone, you understand? First of all an error will prompt saying " Allocating space of data : Error insufficient Space " AND EVEN IF YOU HAD THE SPACE? Lets say we hack the phone and give it 64gb of memory, and give it perfect partitions. ONCE IT BOOTS It will actually have problems, lag, while using the demanding apps.

The newer OS's Versions request mooore Ram , moore CPU powa, more storage space that redmi 9a doesn't have! uhum !

why? cuz the functions actually got smarter uhum !

Dont you see how newer phones have 64 gb of space all by default, tecnology thinks to advance and milk people over and over. They could add 200 gb of space, but no... (Lets wait until its necessary so we can reap the people)

One day an OS SYSTEM will be 25-35 and even 45GB SIZE ! AND THAT DAY YOUR 64 Gb will look like its too small, so you will need to buy the 120-200gb version phone.

Our PC motherboards, cpu's, phones all get old and so obsolete with time, all we can do is recycle them, melt them and make a new modern one, resolder, reball them. That's just how the modern industry works today. You cant just hope to upgrade your old junk/Hardware with the latest Software. One day we will get Android 15, A17 too its already planned ! and this phone will not run it, forget it , hoperfully we will be using opensource Linux OS's even more optimized tweaked than what google and these companies can do in the future. NOT BASED on Android 15 or 17.

You cant just hope to put the new hotdog on the old bread. At least not with the current technology/society