Your equation isn't complete. You can't only care about getting 95% of the way there if the final 5% takes substantially more time than it normally would or worse halts development entirely.
It depends. For some use cases it’s definitely enough and if you’re on tight budget it might get you far enough. But eventually it might fall short and you’ll have to either fight the framework or switch to a native solution.
I believe it’s good for knocking out an MVP if the mobile app is not critical to your business. I would not choose it otherwise though.
