It helps when basically noone hit a good GT double. I think Mas is the best reference, who didn't get dropped once on the longer climbs.
I think Quick Step did very smart a few times with obliterating a small hill before the final climb with Evenepoel in good position, stretching everything out and abusing Evenepoels recovery from short bursts and low CdA.
Evenepoel gained 29" on Mas in the TTT and 1'51" on Mas in the ITT, meaning over the mass start road stages Evenepoel was 15" behind Mas, however those times are affected by bonuses, of which Mas has 20" and Evenepoel 16", so the overall difference between them is 11". Given Roglič lost a bunch of time in week 1 on the mountains and lost far less to Evenepoel against the clock than Mas did, I think we can say that Mas was the strongest climber in this race, by an extremely narrow margin from Evenepoel; I think a case can be made that the best single performances in the mountains were either Vine in week 1 or Carapaz in week 3, but across the whole race it's Mas and Evenepoel.
So really, the jury has to still be out to at least
some extent over just how high Remco's level is in the mountains across a three week race; there were no stages in this Vuelta that really compare to something like the Tour's queen stages with back to back HCs and high altitude; the nearest stage there was to that is where Remco lost the majority of the time that he has lost in this race, but he also had crashed shortly beforehand so we can't truly tell if that was a blip in form due to durability or due to the crash, given the final week he has been pretty strong, but there also weren't any stages as tough as those where he did lose time on the penultimate weekend in week 3.
However, at the same time, the fact he's been able to win a GT so convincingly with his advantages built entirely in the time trial given how much that discipline is marginalised nowadays in comparison to 20 years ago also speaks volumes to him answering the majority of those questions about his climbing and of course as to whether he could keep form for three weeks. Look at where Mas has been in GTs in the last 3 years or so, and extrapolate from that where Remco could theoretically be with the benefit of a couple of minutes per 30km of ITT, but also bearing in mind that Evenepoel is 22 while there we are looking at Mas' performances from age 24 through 27 so Evenepoel has - at least in theory, pending a Cunego of course - more room for improvement too. The one thing that remains as a question mark to his skillset for such races in future is the descending; the Vuelta has in recent years been heavy on MTFs and light on multi-climb stages with significant technical descending, and that has been a question mark around him since the Lombardia accident; however the only riders who were a threat to him in
this race are not the type of riders who could pressure him in that department themselves.