I have your same requirements, but on top of those I'd also like a service that is as robust as possible against SIM swapping attacks, since, for better or wors

I have your same requirements, but on top of those I'd also like a service that is as robust as possible against SIM swapping attacks, since, for better or worse, the vast majority of the financial institutions I use only support SMS as 2FA. I've heard that Google Voice is pretty tough to exploit, since they "lock" the portability of your number by default, and in general contacting Google support is almost impossible compared to the other carriers. For that reason, all my 2FA currently go through my GV number. Though I also read that some advanced attackers have gone as far as faking porting documents to make the ported-to operator "steal" (unfortunately I don't know the right technical terms here) the number from the ported-from one, regardless of the locking, but I don't know if this would apply to GV as well.