I feel it heavily depends on the modem. I used to have a Pixel 5a, which has an SoC (Snapdragon 765G) that was released during the late stages of the transition

I feel it heavily depends on the modem. I used to have a Pixel 5a, which has an SoC (Snapdragon 765G) that was released during the late stages of the transition from LTE to 5G. On that phone, 5G was a terrible experience and my data wouldn't work half the time when I was outside. I switched to a Galaxy Z Flip 4 a few months ago, and 5G is just fine for me since then (i.e. I don't notice a difference compared to LTE). Same carrier, same locations.