physical maintenance and unclogging toilets: you don't need to do this maintenance yourself, you can outsource this to contractors, and even outsource the calling of those contractors to a management company.

knowing landlord-tenant laws inside and out: absolutely, yes, if you are doing it professionally. But this applies to everywhere you are doing business in.

properly evaluating properties, contractors that don't rip you off, etc.: absolutely an issue, yes. This is something you learn with experience however, and on the other hand it means that if you know this, you have an edge. See the blog entry by the mr money mustache guy who bought his house very cheaply from an older guy who didn't know that prices have went up in the decades he has owned the property [0]. So yes, this means that ideally you own multiple properties and have enough capital that you can afford one or two mistaken purchases or contractors, but you also need to have enough dedication and ability to learn. Also note that even with stocks you have this issue, there is a lot of advisors out there who are selling funds with high management fees, etc.

small scale property investment impossible: absolutely true, yes. Real estate investment is something for rich enough people, or at least people with good contacts, not for the average joe.

huge leverage is usual: yes, but on the other hand property investment is seen as a very secure way of investing, which is why such leverage is possible at all. Stocks on the other hand you never get that much leverage for them.

anyone with enough money can do it: this is in conflict to your other point about needing to know how to properly evaluate properties and finding good but not too expensive contractors.

investment being locked up: yes this is true. But moving around stocks too much is also generally a bad pattern.

tenants from hell: yes, this is a risk. Ideally you distribute the risk by owning multiple properties, e.g. an entire building instead of just one apartment, which brings us back to the "need to have money to own real estate" point. Also, you ideally don't own real estate where the rent is cheap but one where the rent is expensive. If it's expensive enough then only rich enough people can afford it, i.e. ideally DINK white collar workers. Those can still cause problems but you benefit from their higher job stability, lower incarceration rates, etc. The disadvantage is of course that it's harder to own multiple properties if the rent is expensive, as you need to invest more, and also if the tenant doesn't pay the rent for N months then a larger sum of money is lost. But on the other hand, if the tenant fucks up the sink and you need to replace it, then having 1500$ rent compared to 500$ rent means that your 3000$ sink pays off again with two rent payments for one tenant, and with 6 from the other (assuming you are mortgage free, the calculation is different if you add in mortgage).

I do agree with you however about your general point. Real estate investment is absolutely not for everyone, as (broad low fee index fund) stocks are for example. It is more complicated and higher maintenance. Still, if you have tons of money then putting a part of your portfolio into real estate seems like a good idea to me.

[0]: https://www.mrmoneymustache.com/2017/08/02/introducing-the-m...