Obviously 90% of the time a phone could be used (though I don't agree it's faster than credit card tap, roughly the same speed) and a card can be used as backup, but it makes ditching a credit card completely not really an option.
If your social circle is anything like mine, it's not some person, it's always one, as in a single person who disproportionately is incapable of maintaining their phone. For the majority of people they're very reliable devices, so this is less "everyone will be inconvenienced sometimes" and more "a few people will be inconvenienced a lot". I recognize that it's still an issue, but those people can keep using cards while the rest of us benefit from tap-to-pay being the preferable option a majority of the time.
I thought "maybe the mayor is speaking to the media" and walked over. Turns out the crowd was people charging their phone from the truck. CNN generously left the truck running there for a couple of days.