Hello Emily. It has been FAR too long and I have missed seeing your lovely self.
That said, it isn't simply fly by night providers and agencies the guys are protecting themselves from by using GV. It is the snooping of girl-friends and wives, who in all fairness probably have good reason to go snooping if their men are seeing escorts.
Regardless, if you set up GV right by using a regular, not mobile, browser to do so it can be set up to function like a regular phone; with appropriate incoming voicemail message, forwarding on or off, and a "do not disturb" function so that texts and VM get caught and not passed forward when it might be bad to receive them.
Wishing well and Happy Holidays to All [especially you].