My latency on EE is usually ~25ms and rock solid on 4G, but I'm 2 miles from the base station and the external antenna has line of sight to the tower. In a dodgy signal area though this could be very different. Three claim 'excellent' 4G coverage here and in reality there is nothing!
I'm 2 miles from the BT exchange as well. Best I could get from that was 5Mb/s with 300ms latency
There's no hope of ever getting fibre in a village of 24 houses so I'm waiting for SpaceX to finish Starlink which should give >100Mb/s
