Once you have paying customers, more features becomes your feeding hand. How do you handle that?

Although ot might make sense for each team. Multiple teams on one app would mean many seperate dev envs (one for each team)?

Generally agree. But as always it depends, heavy applications with alot at stake need more rigurous testing and so they might need more envs... Or?
Starting up/internal app/customer work, sure only two envs 🤷

Keep grinding, you will hit your mark eventually