I remember having ~150Mbps with an iPhone 8 on LTE in 2017. Bandwidth itself has basically never been the limiting factor for the last decade or so. The problem is always data caps, and unless 5G/mmWave/etc is somehow magically exempt, it's not really a benefit (you can now burn through your monthly quota in seconds instead of minutes - great!).
I talked to ChatGPT about it for a while. It says mmWave means you can get 1-3gbps speeds if you're in a covered area. However, most are stadiums, airports, etc.. Verizon has by far the largest coverage, then AT&T.
At least in my daily use, it means nothing. I've also never seen speeds like that when I've tested the phone.
