I have used a pixel 4a and pixel 6a for many years now and haven't had any of these issues. It sounds like potentially had defective hardware, and instead of getting it repaired you just lived with it.
This can definitely be the case. I had a phone that for a year would drop out frequently doing cellular data. I assumed my provider was throttling me. Upgraded my phone and the problem went away; likeliest culprit was the cell circuit in the phone was slightly damaged and running full data comms was causing it to reboot.
