Sounds like my attitude many seasons ago. I started around the same time as you but quit by season 30. So this is my second stint with BB. I've definitely been there with the burnout.
These days with all the infrastructure upgrades and secondary staff available, I think teams need to be doing a lot in order to promote. But at the end of the day it's an economic game. Pull in as much income as possible from ticket sales + arena upgrades. Plus the trainer and youth trainer, consistent game shape, and whatever else you can afford to keep your team rolling.
If you find the grind boring, you can set a goal of getting one of your trainees onto the U21/NT roster. There is an active community on the official Discord server that helps each other out with that.
It just sucks to start over from the beginning if you do decide to quit and come back. I've seen some owners sell their roster and log in once a month just to stay active until they bank $25 million to buy a spot in the NBBA.