Verizon's (and ATT's for that matter) 5G network is behind TMO capacity wise due to spectrum availability.At home I'm in the next tier down on their map being regular 5G nationwide service. I ran the verizon wireless speed test at home and was getting 10 mbps down and 10 up, at work this morning I'm showing 5 mbps down and 3 up w/a 359ms latency sitting next to a window w/4 bars of service in a 5G Ultra Wideband location.
Verizon and ATT initially turned on a spectrum sharing feature that shared existing LTE spectrum with NR (5G) dynamically in order to claim a 5G network rollout. In the last six weeks, VZW and ATT have been able to start activating their C-band spectrum. The C-band spectrum is old satellite spectrum that is around 3.8-4.2 GHz with wide contiguous bandwidth available to the carriers. (As a side note, this proximity to the radar altimeter band at 4.2-4.4 GHz is why the FCC and airlines were concerned about "5G" - specifically C-band 5G)
Expect both VZW and ATT to start having dramatic improvements in overall 5G performance soon, if not already in some areas. Backhaul will also need to be upgraded so even in "ultra" areas things might take a bit longer to really speed up.
TMO's acquisition of Sprint put them about eighteen months ahead of VZW and ATT as Sprint came along with a wide swath of bandwidth at 2.5 GHz (band 41). TMO also held back part of its 600 MHz spectrum purchase from a few years ago exclusively for 5G so they did not share spectrum with their LTE network. TMO quickly deployed hardware and lit those wide swaths of band 41 spectrum up as "5G Ultra-Capacity." I've personally tested it at 500 Mbps+ in dense areas (Pittsburgh, Boca Raton)on my iPhone and would expect VZW and ATT to be able to match that performance by the end of the year in many places.