First, I don't think the productivity gains are nearly what they are claimed to be, and shouldn't be... I think way to many people are getting really lazy and letting a lot of slop through that they shouldn't. Human review takes time and mental overhead.
I've mentioned a few times, that I actually appreciate an aspect of Claude's 5 hr API window... I generally watch, stop, re-prompt and review what comes out. I'm not running a bunch of separate prompts and instances all at once. I'm using AI to plan and do a lot of work... I am getting a lot more output and a lot more value for that time than I could without it. It takes a toll... and the few times I've hit the window on API usage actually aligns with that toll in when I need a break.
I also assume I'm not going to be productive all day... I'll review mail, checkout articles on HN, comment, etc. I'm generally actively in a productive flow about 5 hours a day... with AI, I can be a lot more productive. That said, my current job is pretty locked down and I'm unable to leverage AI for most things... I've been able to use my own computer to write a few libraries/utils that I can then leverage in-job... but that's about it.
Mental work can be more tiresome than physical work, depending on the individual jobs. You aren't "on" all the time. This isn't a statement against or for a 4 day work week, only countering part of the narrative.
Right now the job market is a mess... developer wages are severely suppressed and almost everything is "contract" based and lacking basic benefits like good medical insurance, vacation time, etc. It pretty much sucks. AI is not a panacea, and it's not a replacement for skilled developers. Not only that, but a junior developer + AI can literally be several steps backward compared to a skilled developer without AI or with.
I'm seeing a lot of cool things happen on GitHub projects I follow, a lot of it allowed by leveraging AI... most of the best stuff not left to AI alone. It's a tool. On the flip side, I do think a lot of major employers need to return to actual employees with actual, meaningful benefits and even start implementing profit sharing... There are a lot of people pushing for outright Communism, and they're winning elections in some places. Just from a CYA point of view, it's time to treat the workforce a little better. I'd rather not have communism become prominent in the US... it won't be pretty.