The Twilio 2FA API actually allows you to generate secrets and QR codes for generic authenticator applications now. Check out the documentation here: https://www.twilio.com/docs/authy/api/one-time-passwords#oth...
[1] https://en.wikipedia.org/wiki/Embrace%2C_extend%2C_and_extin...
But if building and maintaining app based TOTP using a library is good enough for you, then go for it. I'm certainly not going to make you use Twilio's APIs, but plenty of businesses do see the benefit.