Roland Perry wrote

The TV pictures towards the end showed about a quarter of the seats empty.
Which is why I'm more inclined to think it's people leaving early to catch
a train, rather than never having turned up at all.

We watched more or less the whole thing, and the empty seats weren't
noticeable until the Olympic flame went out. Couldn't quite see people
checking their watches, but I bet some were. Either that or they didn't
like The Who.