And in true google fashion, it only works with Google accounts; if you send a signature request to a non-google account, it says it's sent but does not work...

There’s a specific reason why google doesnt promote a Docusign like product even when they have superior technical abilities.

It probably comes down to the fact that code is not that crucial but all the other non technical aspects like distribution, supplier relations and marketing that makes a product.

Maybe LLM wrappers turn out to be that way. The model may not matter but the distribution and customer relation etc would matter more.