Typically you also pay franchise tax to California if you live and work there.

Some states like Massachusetts have you pay into an unemployment insurance fund.

Usually you will pay for QuickBooks and a payroll processor like Gusto, which is $960/yr together. So for not profitable entities $800 CA FTB + $450 DE FTB + ...

C Corps enjoy a 21% flat tax rate. They are a very attractive way to conduct business on that alone, if you are actually profitable. The little taxes and fees may make your effective tax rate compared unfavorably to pass through, however if you’re making that little money what was the point then?