The problem is that VOIP numbers, from companies like Bandwidth, are frequently used to perform various frauds. So many financial services ban them because the KYC for real numbers is much better.
Every single one works with GVoice, except Venmo. Chase, Cap1, Fidelity, etc. Not small players.
So while I think you make a fair enough argument for sure, it doesn't seem to be the case when nobody else does it, and makes Venmo seem like a pain in the arse.
That is a closing window and the case in fewer and fewer places. It wont be long until most people would need to fly across the globe or get involved with organised crime to pull that off...