Isn't that the opposite though? Having a store for the customer to get face-to-face support is sometimes necessary even those who prefer it all to be online. It acts as a stop gap to people otherwise low support customers.
The newer upstarts you mention are self selecting for customers who would do everything they can to never make a support call. They are just another form of having a 15 minute wait time because online only is it's own customer service barrier.
No. In the case of cell phone carriers, the only times in the past 10 years I have ever darkened the door of a retail store is times when the carrier was too incompetent to let me get my problem solved another way. For instance, there was a time at AT&T where if you had acquired a brand new unlocked iPhone that needs eSIM, you needed to receive a physical piece of cardboard printed with a unique QR code on it in order to activate it successfully.
I’ve been with US Mobile for years now and never once felt the need for a physical store.
With sims switching to e-sim there's basically no reason to have in person support for cellular service. There's nothing they can do, outside of what they can already do online or over the phone. Like, if you go to an AT&T store with a broken e-sim they can't wave a magic wand. They'll probably just reset it on their end, like they could do over the phone.
Centralizing support generally saves money.
There's a lot of reasons for this. One of them is that it tends to be a lot cheaper to have one building in Denver to host support people than to have many buildings in every city.
Besides that concept, they're selling telephone and data services. It makes sense to -- you know -- make use of them.
When we had a telephone issue back in the landline days, we didn't load ourselves up into the car and go to a store to get help from someone in person; we instead used the phone.
(That may have been done by using the neighbor's phone, but whatever. We still have neighbors and not all of them are dicks. And these days, we still have cell phone stores for those who can't empty the water from a boot. The days of brick and mortar cell phone sales are not, at this time, numbered.)