Heathrow, Gatwick, Stansted, Luton, Manchester, Birmingham, London City, Glasgow, Edinburgh, Aberdeen, Bristol, Newcastle, Belfast Aldergrove.
EGNX will still be there, it's bigger than EGLC, EGGD and EGAA.
East mids & Liverpool are bigger than london city, Aberdeen, Aldergrove & are basically on a par with Newcastle. But yeah...
Of course we have not only BFS but also BHD, two airports within shouting distance of each other largely competing for the same traffic (a combined market of >6.5m, not too far behind GLA).
We can debate till the cows come home why a city the size of Belfast needs two airports, and whether the fact that we do is detrimental to route growth and sustainability, but the fact is I don't think either of them is going anywhere in the foreseeable future.