You can still do side projects when you’ve got kids. You just have to treat your priorities seriously, which usually means having to give up most of the netflix/social-media time. You also have to realize that in a two parent household, you don’t usually need both parents looking after the kids, and it’s better for both of you if you take turns (for your sanity AND for your free time).
It can, but it really depends on the personalities of you and your partner. It works best if your partner also has some independent work they need to get done (or enjoy doing, ex a hobby).