I've had good luck with ozempic and lamictal for this. They just give me more discipline. lsd has the effect of giving people a more accurate perception of time passing, but you probably wouldn't want to be on that all the time. I'm hopeful that we'll find the perfect productivity drug soon. So many things kinda work already.
AI has has been the opposite for me. By doing all the easy stuff for me, it's allowed me to spend most of my time solving hard problems and being creative, instead of spending most of my time doing gruntwork. If anything I'm more sharp than I used to. It's a double-edged sword.
This is only my personal experience of course, but for making little tools for automating tasks or prototyping ideas quickly AI has been a game-changer. For web development the difference is also huge.
The biggest improvement is when I'm trying something completely new to me. It's possible to confidently go in blind and get something done quickly.
When it comes to serious engineering of novel algorithms it's completely useless, but most devs don't spend their days doing that.
I've also found that getting a software job is much harder lately. The bar is extremely high. This could be explained by AI, but it could also be that the supply of devs has increased.
I personally keep a log of breakthroughs, along with the narrative that lead me to it. I read through it occasionally to see what didnt stick and try again.