Honestly, if you use Tailwind or Chakra UI it can’t be too bad and that’s what most SaaS use these days.

I could possibly don’t see how it solves my needs if it does it in a crappy way too.

I think initially people just build things to validate it or even validate it before. If it solves a problem and people start paying for it, then is the time to optimize the user flows and polish the UI I would say. Do not invest too much time into something that might never work.