I was genuinely impressed that when my T-Mobile 12 showed up on launch day, even though I live in a small town in a rural part of California, I immediately was getting 5G, and the speeds were (at least versus the last time I checked a few months earlier) maybe 3-4 times faster (100-200Mbit). It's also more reliable than my wifi cable connection (which seems to be a combination of erratic Suddenlink service and crappy Suddenlink router), so half the time if I'm on a 3-hour Zoom meeting for work I end up switching to cell because my damn wifi keeps dropping out.
After all, even 30Mbit is enough to do just about anything I want to on my phone without it being an issue, so ultra-speed connection if I'm standing on the sidewalk in downtown San Francisco is absolutely worthless. The only benefit I'm aware of with mmWave is that it can handle extremely dense crowds at a stadium or something, which is an incredibly narrow use case.
Verizon does actually have better middle-of-nowhere coverage out in the woods here, but it's slow. so I'll take T-Mobile since I'm far more likely to be on the phone in town than walking in the forest.