Those shouldn't be prohibitively expensive; even small businesses in the US can typically afford one.

Having an accountant is one of the hallmarks of a legitimate business.

If you're doing it on your own without a professional to watch out for you, and advise you, and take care of the details so you can do more important things, it isn't a company, it's a hobby.

Even hobbies are sometimes better done with an accountant. if you sell your garden surplus at a farmers market for example. They are not expensive if you only need a little help and can save a lot of trouble.

"That's just moving fast and breaking things and disrupting industries." - someone in SV right now reading this, probably.