PayPal requires you input a phone number now? They've blocked Google Voice as an option. There's no way this isn't to harvest data.
If you need 2FA, they have my email. If they want better 2FA, they can get a U2F or TOTP option from me. It's not about security, 'cause you wouldn't have an 8-20 char password limit or even allow SMS as an option if you cared.
Everyone knows SMS is busted and the only reason big corps want it is to cross-reference all of this with big data because so many services require your phone number. This is why WhatsApp is in controversy right now because Facebook wants access to your contact list to build up its advertising monopoly (and because encrypted message, kinda hard to read).
All of this because I wanted to buy a t-shirt from a Russian emo band I found nostalgic. Shout outs to Bird Bone anyhow https://birdbone.bandcamp.com/album/-