Yup, I recently travelled to Hong-Kong from the the UK and noticed just how much better coverage was in the city. I expect poor coverage when I'm in Yorkshire, but there is no excuse for just how bad London's coverage is. A lot of it seems to come down to which carrier you are on, a quick look at coverage maps [1] and you can see what carrier you are on is really important in some parts of the country.

[1]:https://www.nperf.com/en/map/GB/-/2012851.Three-Mobile/signa...