"Gathering mental capacity to simply know what next I need to do" is not a waste. That is work. In fact it is the most important work with LLMs. If you spend all day in a hammock dreaming up what next needs to be done (and it's the right stuff), and then type a few sentences into the LLM to generate it overnight, that is better time spent working than spending all day cranking out 20 PRs that are of mid-low value.

Yeah, if you're wandering in random directions all day long (20 PRs a day is rarely working towards a clear goal) then you're not going to get far. Taking some time to figure out where you're headed is probably way more beneficial in the long term. And it's also something LLMs suck at, they interpolate extremely well but haven't got a clue what's next.