I'm not knocking the idea of running various maintenance tasks while the computer is asleep. The original post mentioned installing updates, and I agree that and your ideas make a lot of sense. It's not even a very new idea — I seem to remember the Wii would download updates using its ARM processor while the console was asleep.
OP specifically mentioned "discord or slack showing [them] online", and that's the use case I was questioning.
I do think that, even for legitimately useful uses, I'd still want the ability to turn it off. No matter how low the power draw, there may be times when I need to stretch my battery life a little longer, and I'm in a better position to know and plan for that than the OS is.