I've worked in these Agile teams for my entire career so far. I have begun to believe that standups, in the way that most companies conduct them, are against the interest of most developers. It feels like I need to justify my position every day, and that I am only as good as my last feature. Sprints are basically scientifically optimised crunch. It is like the last stretch of a project every 2 weeks. Just put in the extra energy "for the sake of the sprint". Pull all-nighters, just so that you can be told in your planning meeting that we are "agile", and the requirements are changing again.

Disclaimer: These are subjective opinions, and I recognise that some developers thrive in this environment. Also, this is a comment on Agile in the wild, rather than in principle.