What a sane person would want to install a shitty carrier app just for that? There should be a way to do it via their web ui in the least

That's not a solution. There is no other carrier that has the coverage I need.

The problem with eSIM as a concept is that it puts too much responsibility on the carrier, and there are way too many shitty carriers out there, and with the cost of building a network and the limited amount of spectrum, mobile carriers are not a functioning free market.

So I have Xfinity and your supposed to be able to do this via web. I was riding my dual sport deep in the woods and lost my phone. Tried my damnest to activate an s21+ I had in a drawer and it kept kicking it back. I go to store and they cannot activate it as it's "not supported by their network". They try to sell me a new phone. I'm frustrated and on like day 3 no phone so I said fuck it I'll buy the cheapest Motorola on the shelf, but under one condition. I refused to buy the phone or continue my contract unless they would give me a physical sim (they tried pushing the esim HARD). I got home, took the sim out of my Motorola, popped it into my "unsupported phone" and it worked fucking fine. Esims are just another complication and way to get tech illiterate into the store. As long as I can I will never let go of my physical sim ever again.