If you had support starting a new business what would you want to do, and/or what type of service will fill a significant need in a way not currently available?
In general, without revealing your most original, "top secret" ideas:
What kind of service/business would you create if you had funding and people helping you succeed?
My own marketplace that accepts any traders after taking a test to check they not scamming idiots. Then all the secure nessery features like verification of phone and all that if you a vendor. But use escrow obviously. I can put collateral into another address to secure my customers funds are safe and if I do steal the escrow I habe setup will release and give them the funds back. Obviously that will not happen but it helps to build trust in customers. Then I would have the market use its own currency which I will release as a pow coin which users can buy or mine and use it on the market. Then simply expand and grow from there.
Also I honestly don't care if people read this. I know its a good idea but guess what 99.99% of these clowns are not devs and couldn't come up with their own idea or even have the slightest idea or clue of how to manage and run a business. All they know is a quick profit through theft.