Sure - and I absolutely agree there’s a lot of bandwaggoning. People who never paid any attention to a certain stock/train when they were in service appear en masse for the last event to say they did it.
But the comparison isn’t really valid for the 73TS, imo. If the most recently stopped stock was 59TS, maybe, but many of those who would attend a 73TS trip in at least another three to four years may not have even been alive in 2000. I was aged 7 - even if I wanted to be there I couldn’t have been! The more recent disposals are a far more useful barometer, and from @Alxxxs’s posts I suspect what they’re benchmarking on.
Personally, I made sure I was out for the last day of the C stock - and I was the only person on the train for the first trip of the day - but I avoided all of the D78 trips aside from a Tower-Richmond-Upminster-Tower and the afternoon of the farewell tour because they’re trains that have no interest to me and I certainly won’t miss! The former was to recreate a photo that’s now in the LTM archives, and the latter was as part of the stewarding team.