Why the hell are there always way too many required features in way too little time?

Because what we do is magic ! And magic doesn't require time of course :D

Hahahaha
Welcome to the beginning of the overworked devLife.
but your only working on 1 project at a time right?

We are 3 devs on our team. They have more dev experience, however I've been working on this backend for 2 years. the other 2 a few months. Everytime we estimate storypoints they seem to be lower than I am. PO said in a jokingly way multiple times while estimating "put one less coffee break in it". And yet, everytime we have too many features and they take longer than estimated....

I'm ranting about this after 10+ years of being a software engineer. It really feels like no matter what happens, despite best efforts, there is always too much work to do to successfully hit the deadline without some kind of scrambled response.