Didn’t like that requirement either, so I used another site to get a virtual phone number to authenticate. There’s a bunch, but I’ve used this site for both Telegram & Discord:
Check out “The Amber Room” on telegram, it’s the spiritual successor of The Grove. Very actively updated with a secondary requests channel that has never let me down.
Just searched on a public telegram indexer I use and found probably 20+ groups full of private STL files. Some of which would probably make GW pretty upset