The problem with the UK is that because we were early users of 2G, the majority of cell sites were put in place to suit GSM coverage
This is the invariable excuse. We have a crappy, badly-planned rail network because ours was the first. I imagine the same excuse is applied to the road network. It used to be claimed that German factories were much more efficient than British ones because theirs were all destroyed during the war, so they started again with new machinery (I haven't heard that one for a while - there can't really be any factories still using pre-war machinery).