May I ask what you base your opinion on?
Being born at 8,600 feet above sea level can have its advantages.
Its not a given but Bernal gave strong hints at the 2019 TdF. The shortened stage 19 he was untouchable the higher the roads went, he just rode away from Geraint Thomas on Col de l'Iseran. That day was just as sir fly described - the longer the effort, the wider the gap.
On Pogacar, in 2020 TdF he lost 15 seconds to Roglic on the summit of Col de la Loze (2,304metres). That stage was won by another Colombian - MAL. It is only one example but it did raise question marks.
But I haven't seen enough of Vingegaard at high altitude to form an opinion on him in that terrain. People can point to stage 11 in 2022 TdF but I think the outcome was due to Jumbo's great teamwork and Pog blowing himself up - not the altitude?
Everyone responds differently to altitude it is difficult to predict until it actually happens. But even if Egan gets back racing I think there are still question marks on his back condition?