He got a very good deal, he is lucky that Twilio acquired his company that I've never heard of.
Authy replicates data so you can have your 2FA on multiple devices and easily restore them if your phone dies.
The other thing they advertise us 2FA for actions. So not just on login, but on actions. Imagine getting a 2F push notification that someone is transferring 5k out of your bank account, accept?
That also means the price isn't just logins, but could also be sensitive actions!
And why not Google Authenticator? Some people either want to avoid Google products or be more appealing to customers who want to avoid Google. I know of Authy since itch.io use them.