It doesn't work on my computer, nor does it work on my phone when I'm traveling (different SIM), so I give a damn. WhatsApp, iMessage, Signal etc. do both. I really wish there was an open, federated standard (and no, RCS is neither), but until then, I'll use what actually works for me.
SMS just sucks, and I hate that it's become so ubiquitous an authentication method when it's not even secure.
I've never understood why so many people still chain their identities to physical SIM or even eSIMs. It's so fragile.
Unfortunately, more and more services are declining to send to VoIP numbers because of seCurItY, so it's a game of cat and mouse.
Fortunately SMS is so expensive in parts of Europe and it's not allowable anymore to use SMS by itself for online payment authentication, and both issues combined have slowly been pushing companies to explore alternatives.
There unfortunately seems to be no such pressure in the US. Passkeys could solve the issue, but probably increase support request volumes enough for most companies to not bother unless forced.
Unfortunately that means that my cell number which I wanted to temporarily park into VoIP while abroad is now permanently VoIP.
If you're lucky, the service you care about only validates at number registration time, not at text sending time, and you can get away with it indefinitely, I suppose.
Most of the reason to deny voip users is that many voip services give phone numbers away like candy and then those phone numbers are used to abuse other services, so checking the original carrier tends to be enough for abuse screening.
Some use cases want more though. Banking KYC has some back channel to get subscriber identification or be alerted when ownership changes; those institutions may be willing to pay for current carrier lookups and deny usage of numbers where they don't have a back channel to the current carrier.
Living in a place where getting a replacement sim is gated behind obtaining an id from the police tied to your national id number, I wish there were other identity systems which were as robust. Much easier to get back to normal operations when the id device becomes damaged or lost with a physical sim you can shove into a cheap replacement device, than relying on backup services you need one of your digital id devices to access in the first place, especially if they're all lost at the same time in a house fire or something. The police will presumably get all my photo backups and savings if they ask nicely anyways, so the big threat to the single point of failure doesn't have a great marginal impact, while I dread the possibility of having to recover the accounts I can't get back through the local legal system given the poor 2fa recovery ecosystem.
If the device can get damaged or lost, then the SIM can too. To buy a physical SIM or rent a virtual number online, in most jurisdictions you need to provide ID docs these days, so nothing is changed there.