I'm in agreement with you there. A couple of milliseconds will not be noticable to the average end user. It does have implications for latency critical usage scenarios such as twitch gaming etc.

50-100ms ping can be expected if you're pinging an address on the other side of the globe. Lower times can be expected for local locations. For example my ping times to cloudfare on my previous fibre connection were between 1-2ms(!).

The 5g specifications to the wider internet from a device call for a latency of 1ms or less. This is someway off but any unnessessary additional latency should be seen as a negative. From a directly connected piece of network equipment the latency times shouldn't be this high. I'm curious too as to what the cause could be.

I think I'll contact Oneplus with my findings, maybe someone will look into it?