Are you sure you aren't talking down LGW because you're an incorrigible cheerleader for LHR?
No I fly from Gatters as often as I use LHR. LGW is great at what it does, leisure focused and p2p, it's a huge asset in that space.
LHR was woeful for years, decaying terminals, end of life structures and basically coming apartt at the seams. Then a lot of money was spent to undertake a strategic rebuild to make the airfield and terminals fit for a 21st century audience.
MAN is now in the same place LHR was, infrastructure lagging well behind with bespoke bolt ons versus strategic decisions made to drive sustainable change. Multi terminal operations with alliances split (not a huge issue tbh) and some building being used for traffic for which they were never intended, T3 is a clear example.