If your target audience is businesses, not individuals, then you can go a very long way with fully manual onboarding, invoicing, etc. It's different for things like consumer services or e.g. forum users, but why couldn't you manually vet every business your business trades with?
Does it matter to you? Yes.
Will you admit it? No.
But yes, these are all decisions we need to make. That manually accepting is some serious dedication. Do you have kids?