Mom used to put a dime in my sneaker. When it was time to get picked up (pool, bowling alley, whatever), I’d call from the pay phone, ring three times, and hang up.
In many systems, the ringback tone heard at the calling phone was not synchronized with the ringer that sounded at the called phone. So “ring me 3 times” wasn’t always literally controllable.
I don’t know how Google manages to fund its Google Voice. Advertisers? Maybe they show ads that they think are associated with kinds of businesses that you called? But it’s free in the USA still. While Google does some bad things, so do normal phone companies... to me, trying to keep track of who is “worse” is a wash and not even a spiritually gainful pursuit. Now if someone was clearly “better” I’d choose them, but I don’t know who.