Never use your real phone number with services like Facebook. They don't need to know your phone number.
You could use a fake phone number service, but ultimately somebody else could just use this to login to your account. You also can't guarantee you are able to use that phone number again when you need to get back in.
The only real option is to not use the service at all, which is easier said than done when your family, friends and even employers use (and require you to use) the service.
I should not be required to have a mobile phone and even if they do they shouldn't need my phone number.
Pick a different 2FA method.
Define "services". In the last decade I have signed up for exactly 1 service that required a phone number (Telegram), and somewhere in the region of 8,000 that didn't.
All major IM platforms (WhatsApp, Signal, LINE)
Any dating app I ever tried to use
The only prepaid SIM cards you can get without the full procedure are data only
Increasing amount of services do either/or of country restriction and detecting and blacklisting virtual numbers.