I wouldn't expect a mid-ranger phone to be fast and completely reliable. That's why it's just a mid-ranger. The price is a compromise; you get shitty radio hardware and shitty software so you get shitty videoconferencing.
Is a mid-range phone today worse than a high end phone 5 years ago? Because the hardware at the high end 5 years ago could handle it decently iirc. Though it really depended on your internet connection, latency and other issues much more than the hardware on the device really.
For the most part, given the margins at the high end, it's not significantly better.
For the most part, given the margins at the high end, it's not significantly better.