No one else trying the same thing as your startup is a far bigger problem than being second. If no one else is doing it then you have to single-handedly prove there is a market, spend the money to educate people that they have a problem worth spending money on, and do all the work to figure out what the problem is and how to solve it in a way that represents value to your customers. That's really hard.

Leaving those problems to someone else and being second with much cheaper solution that can undercut the company that was first is often a pretty good strategy.