I generally think of it this way: a manager tells you what you have to do. A tech lead tells you what you'd be stupid not to do. You won't have much formal authority. At the same time, you hopefully won't be under much formal authority if you chose the right startup.

At the same time, you earn a significant amount of "political capital". People will probably give you a certain amount of deference. And you earn the unique benefit of having a unique perspective on something.

Don't think this can't all be taken away from you, because it can, either due to political or technical considerations. You can get marginalized by someone with an agenda, or you can lose the respect of your peers with a few wrong decisions.

The good news is that you really don't need great leadership or people skills. You just need to convince people that the benefit of having worked with you is greater than the cost of having to put up with you. People are willing to forgive the occasional foot-in-mouth incident or the occasional screw up. You just have to make sure people know what benefits you're providing them in return. And having been objectively right or gotten great results will more than make up for having accidentally hurt a couple of feelings in the process.