But we were not always the biggest club in Britain and its unlikely we will remain the biggest club in Britain forever.
so how is it bollox?
I generally agree.
Empires rise and fall (and sometimes rise again).
‘Past performance is no indication of future performance’ as all financial products have to say.
The ‘uniqueness’ of United stems from the tragedy of Munich. The world suddenly knew a lot more about a single far away football team, in a well timed (from a football point of view) global media event. 10 years later this was reamplified with a risen from the ashes team winning the EC.
That’s a strong and compelling narrative, and a very decent ‘product’ to sell.
Prior to Munich and coupled with the EC , United were on a level with umpteen clubs, rising and falling, jostling for top dog for comparatively small periods of time.
Although
Uk crowds (ie supporters) were generally the highest from the end of WW2 - still never understood that - (other than the media narrative of Old Trafford being bombed and it’s effects and perception?)
The comparative wastelands of the 70’s/80’s were sustained on the recent past. Liverpool rose from the ‘umpteen’ to become
the club of that time.
And then the empire rose again in the 90’s.
The ‘umpteen’ dwindled to about 6, then Chelsea made the leap, and later, City.
It was into the 90’s/00’s that ‘entitled’ became an overused word, and a very negative one.
Used by Liverpool fans on the back of their previous 2 decades, used by United fans on the back of the post-Munich and current (at that time) steamroller success.
I doubt that United will lose their title of ‘biggest’ club in the UK. It would take a generation (20 odd years) of being a yo-yo club to begin denting the acccumulated support. And that has as much chance of happening as Trump acting like a President.
So, to answer the question of the OP title: never, because it never was to anyone other than a club’s own fans.