X rival Bluesky was available by invitation only until today, but now everyone can join. The question is, will they?
Bluesky was announced in late 2019 by then-Twitter CEO, Jack Dorsey to develop a decentralized standard for social media and has grown to have over 3 million users.
There's an app, on iOS and android, called "TextNow" which is totally free (with ads of course. Out the ass) that allows you to text/call over WiFi. It's not the only app, but I have tried a bunch of these, and most are total scams. This one is probably some level of a scam, but it works for getting a text-able phone number which isn't your actual number. You can keep it too if you sign in at least once per 30 days and send a text. I've here maintaining a "throw away" list phone numbers for... years... now. (Don't ask)
You could easily make a throwaway email via VPN, make an account there still via VPN, and always use the app via VPN to maintain some amount of anonymity. If you wished.