I don't know man, $500k is a LOT of money to even pivot to the next Uber for X. I might be totally wrong, but I think you are just burned out.
Best of luck!
Personally, I think more healthy skepticism like this is needed in startups. Everyone being completely convinced they can pivot to the next Uber for X is what scares me that there's a bubble and makes satires like HBO's Silicon Valley so poignant.