For many people it's literally impossible to self host anything, whether it's because of lack of decent hardware resources, and/or because of a lack of technical knowledge, and/or because of a lack of time, and/or because of a lack of energetic stability, and/or because of a lack of monetary resources, and/or because of a lack of mental and/or physical energy, and/or because of a lack of someone with some or any of these; and of course, all of these things can be and in fact are intersectional with each other.

So that's why any managed alternative it's still a good alternative for these people; obviously, only if they're as transparent and reliable as humanly possible.

I myself only do use Disroot's (and maybe Nadeko and a bit others) services because I don't have the hardware, the money, the energy and the enviromental resources to be able to properly self host, and even more, I only use the free tiers of these services.