> If you follow basic things like single responsibility principle and layers you don’t need code documentation.
Yes, write the code so cleanly, and with such good names, that you don't need documentation. Absolutely.
But the code is never quite clean enough, and the names are never clear enough, and the people coming later don't know everything that you know. So write documentation anyway. And not just "sling something out there" - write the best documentation you can; write it as well as you write the code.
(No, I don't do as I say. But it's the right thing to do...)