As an option, I'ld explore a side-hustle first, see if you like doing that enough before going all-in. Your goal for side-hustle, 20k MRR or gross margin monthly (ecom). Choose a metric that's real. If you can't hit it on a part time basis, you probably won't make it on a full time basis (for venture style startups that is. If you're targeting lifestyle growth levels, you can always do that part time. So what if it take 3x longer because you spend 2 days a week instead of 6 on it. ).
Run it like a startup, eg. hire folks, pay for them (out of your salary), manage them, build out specs/build stuff/etc. Do all the things you would need to create a startup. Low risk, a little expensive as an experiment, but if you didn't leave your posh job, you can afford it. eg. it's a 100-200k experiment, but that's 'ok'. You'ld have certainty.