Fewer lists are probably better. I have several, but I only use the default reminders list and a grocery list called “grocery”

I have shared lists with my family for things like school and medical (grocery is shared too), but I’m the only one that looks at them, so I’ve quit using them.

If you have a lot of lists, then you’ll have to decide which list to add the reminder to, and that’s extra friction that you don’t want.