Allow normal 2FA, not just Authy
I use a master password solution that stores my 2FA authentication and I'd rather not be required to use Authy for one app (this one).
yubico key could be another option
Seth G commented
In my case, I don't trust Authy (another 3rd or 4th party) to keep my data safe. I'd like to retain control of my own means of 2FA as much as possible.
Like OP, I have a vault that handles passwords and 2FA.