I'm not a Buddhist, but because of the stressors of my previous career I sometimes joke that I accidentally recreated the fundamental tenets of Buddhism in order to not wash out. One of the things I've come to realize is that the slog feeling you describe is something like the concept of 'samsara' or "cycle of aimless drifting, wandering or mundane existence" per the smarter people that edited the Wikipedia article. But that it's still possible to find meaning and satisfaction within this paradigm.

Maybe another tool would be to try to mix it up more… so each day feels different.

Especially at work where we have always been busy but lately there is no break, no time for modernization or learning or technical debt, we just move from one epic to the next epic, no fanfare, no launch parties. Just each of us at home working alone.