Most sponsors don't hold shares unless for the stock pops way beyond the $10. For the average company, you may end up as a public company with no cash raised. This can be mitigated by a concurrent PIPE, but otherwise you're SOL.
No, you're not coming out ahead. You're roughly paying a 20% cost of capital. In today's frothy markets, you might make up for that in the public markets, but it does seem that mostly second tier companies are going public through SPACs.