I might as well sign-over my pension check to Amazon. NOT!!
> They used to bundle a low rate cellular data connection with Kindle ebook readers so they could sell you an ebook anywhere.
That's different. e-book transfers will tolerate seconds of delay, so can run absolute lowest priority. Wait for all the talk-phone customers to take a breath at the same moment. It is only a minor annoyance to wait minutes for an e-book. And you only "need" the first 10k of e-book to start reading, the rest will trickle in faster than your eye can read. Interesting use of a switched packet network, buying the micro-slices of silence, but not generally "good service" for talk-phone or Facebook data.
> Limits on data speed and capped limits, access to 5G spectrum, tethering, and streaming video quality...
I just changed carriers. In my neck of the woods, if you have the wrong carrier, you have to stand in the driveway in a snowstorm to get one stuttering bar. AT&T is by far the best signal (I can see the tower in the cemetery) but I'm not paying AT&T's rates for my modest needs (10 minutes and 0.12GB per *month*). So MVNOs. I did not find any which excluded 5G (OTOH, none promised 5G would work). All listed data caps which may be unnoticed by many punters. All offered IMHO degraded video speed, though it was not that long ago that the median cell stream would have been considered excellent home cable/DSL service. My last cell plan nominally banned tethering but it worked great for an hour of power (and cable) failure, so that may be unenforced until all your neighbors hop on.
A 2-year buy of Tracfone cost $6/month in 2021 but Tracfone is falling apart (or Verizon, same thing). This year Cricket (AT&T puppet) is $30/month with a buggy customer portal but great service for my needs.