I tried it, I wanna say for a month. But I seem to recall some services that used a phone number for 2FA wouldn’t accept the number. I suspect likely because the area code block was associated with VoIP, or something similar. So I didn’t bother keeping it.
EDIT: my compromise was to use an app to block all callers not on my contact list, or whose number I hadn’t called first. I know that doesn’t help with anonymity, but I had to keep my expectations realistic