Right now we have Pogacar and Roglic who stand out, a tier below that Bernal (if Vingegard can at least replicate what he has shown at the tdf I could see him on the same level) and then a larger group of GC riders who are of very similar potential so that nobody stands out- well, Carapaz might just a bit.
So unless all of those 3 (4) show up (and finish) at the same GT in top shape I dont think it well seem like we really have gotten a strong GC field, as the first rider below any of those guys will always be a one out of that generic and little exciting group.
I agree with this assessment of talent. Only the 2 Slovenians are the complete and consistent GC package right now. Bernal's back is still a question mark to me. Dumoulin pre injury was also on Roglic's level, at least.
Too early to say about Vingegaard.
But you can only compete against the field you have, and there are different factors that can make a race hard or easier. We just can't list a bunch of names or cite margins of victory and declare that the field was weak or strong. Sure, this Vuelta was a relatively easy win for Roglic, but the start list was "strong." A lot of things transpired in some crucial moments, and voilà, we have a "weak" field...
Was the 2020 Vuelta a strong or weak field? I thought it was a strong field with some very motivated riders, and Roglic rode a helluva race. But you could certainly argue otherwise, because so many GC riders are inconsistent. For example, what is Landa's true level? We just don't know.