Many providers don't give you a choice. Many major banks default to using SMS for 2FA. I'm sure if they get breached the government will bail them out so why should they change?
I use a GV number for 2FA over SMS as the last mile solution.
Even when I did get a "real phone number" (that concept irritates me to no end), one of these first required me to send a phone bill as a "proof of me owning that number" before they would let me set it for 2FA.
I guess that's just what happens when blending/confusing the three distinct concerns of spam/fraud protection, 2FA, and user identification (for inbound P2P payments) into a single identifier.