N.B. the distinction between startup and small business.
The US is not a very friendly place to run a small agency or an artist's studio - here in the UK it costs a few pounds to register a company (or nothing as a sole trader), and doing accountancy and compliance is WAY easier. It's fairly simple to employ someone in the UK, but it's hard in the US without a league of accountants and lawyers behind you - hence why stuff like Stripe Atlas exists. I wouldn't run a business in the US with revenue below 150k.