My company uses gRPC and it's an absolute nightmare but not so much to the point where we'd use a company like this to add on MORE costs to our infrastructure.
It baffles me people choose buzzword technology because "ex-googler" or whatever when 99% of companies that choose it will NEVER hit the scale it was meant for. Best of luck to the sales team. They'll be the driving force I'm sure.
REST is fine for 99% of companies. Long live REST.