Googling "google one phone number" did show me a potential scam result in the infobox at "gooogle-live-personn" on google sites that obviously isn't official. You can't make this stuff up.
Only after all of this it links to another number, which from what I can tell is a scam phone center which will offer to help you with your account for some money. I really wonder if they're betting on everything else being so hopeless that a person will eventually try to call this other number after trying all the other options before.
It does tell you something about Google support if scammers can do that...