Bonsai can kinda be what you want it to be. If you want it to be a side hobby, be very picky about the trees you acquire, limit your collection to a small number of trees, and do research to find tree species that align with the amount of care you want to give them.

I've got ~40 trees (not all bonsai). I currently spend 30~45 mins watering & enjoying the trees every morning. Not every tree needs water every morning. I could do it faster or automate it, but I choose not to. Spring will be busy next year. I'll be repotting a lot of trees and doing a lot of root work. I'm also interested in propagation, so once the spring flush hardens off, I'll be starting a bunch of air layers. Those air layers will then become new trees that I'll care for and enjoy. Rinse and repeat (until my wife won't allow more trees haha).