We're with AT&T, and I just recently went to get new SIM cards for me and the wife's new phones (since both our cards were 6+ years old lol), and my first stop was the closest store, which wasn't a corporate store, and they said the non corporate stores were no longer giving out SIM cards, they were only doing ESIM's.
They said AT&T is phasing out SIM cards, they weren't sure why but they had a few suspicions... one was to keep people from switching phones as easily (keep them locked into a phone/carrier longer?), make it easier to keep track of users phones (theft/who knows what else?), that the constant switching could mess up account info, or the fact that they might start charging an activation fee each time you switch the ESIM to a new phone...which requires a call to your carrier and going through the activation process like a new SIM card. I would suspect the last one for sure, but it sounds like overall it's for more control... which is never good in any situation, for the consumer that is.
BTW I got 2 new SIM's at the corporate store. If you need new SIM's I recommend you get them now, because AT&T at least is definitely trying to discourage folks from using them. I will never buy a phone that is ESIM only until I'm forced to. I highly suspect ESIM only phones are a way to tighten the noose around our money even tighter.