There's a list and history in [1] - apparently in 1945 there were 720 airfields in the UK. Most of them subsequently closed, or converted for civil operation.
The legacy of WW2 means, to this day, the UK has more active airfields than they have modern fighter jets.
The UK and most every other western country. Canada has 500+ airfields and nowhere near that number of jets. The US has over 5000 airfields and, again, nowhere near that number of jets.
We have two major air forces (RAF, USAF) operating in the UK plus a naval air service and army air corps, so an abundance of airfields is unsurprising…
The legacy of WW2 means, to this day, the UK has more active airfields than they have modern fighter jets.
[1] https://historicengland.org.uk/research/results/reports/7018...