If Pogacar could outpunch Van der Poel, out ITT Remco, and outsprint Milan he would be like J.H.Klabo.
This kind of dominance is either very suspect, or completely normal - because all of the XC events and most of the big bike races essentially measure the same thing and one guy is better than the rest on this thing.
How can one person by so much better than all of the rest? Maybe that's completely normal in niche sports.
There's a combination of factors.
Part of it is that the increasing homogenization of the calendar has led to a heavy increase in mass start distance races that stay as a pack quite deep into the race, a heavier sprint-bias to the calendar and shorter, easier circuits to improve the stadium fans' viewing experience, resulting in frequently taking things to late-race short uphills or sprints at which he is the best. Think of the many years of women's cycling being dominated by a certain type of rolling-to-hilly circuits parcours; Marianne Vos was unquestionably the best in the world at the time, but the proliferation on the calendar of the specific characteristic of race that she was best at, and the marginalised nature of true specialists in areas of her weakness (such as TTs or multi-climb high mountain stages) meant her domination was greater than it would have been otherwise.
Another component element is that Norway has a huge budgetary advantage over most opposition, spending far more on optimising ski preparation and so on than anybody else. In addition to this advantage, they have been shown on numerous occasions to be willing to push the envelope in terms of acceptability, such as being caught breaking closed course regulations to test skis at these Games, and the very infamous bus full of asthma nebulizers back several years ago. And in the Scandinavian Tour a few years ago they were as blatant as having a point-to-point race in heavy snow where they put machines out to clear the tracks right in front of their own skiers.
Further to this, you have the fact that Norway's level of dominance has led to an exodus of talents and funding from many nations, especially seeing a bleed over to biathlon where the regular shooting breaks at least give a chance for people to win if they aren't the very best, if the circumstances are right on the day. We have also seen some Norwegian athletes - Hans Christer Holund and Simen Hegstad Krüger are two notables - complain about the Norwegian authorities further tailoring things for their preferred golden goose, either by way of the courses used or by their selection decisions.
For a long time, men's XC had devolved into a straight Norwegian national championships, and the only ones that seemed to be able to break up that hegemony were the Russians, especially Aleksandr Bolshunov, who emerged into the only realistic rival for Klæbo. He won the skiathlon and the 50k in Beijing, and also took the decisive leg in the winning relay. The exclusion of Russia for political reasons has therefore removed arguably the only man who could realistically be a threat to Klæbo on these courses.
The point is really rather that Johannes Høsflot Klæbo is really, really good. This there can be no denying. There is a good chance that, were we seeing competition on a fairer financial footing, on an older-style variety of longer and more challenging courses, and if his main rival was allowed to start, he would still be winning the majority of the events that he is. But these are all factors that have made it easier for Klæbo to become as dominant as he is, and it's why you will still see "yeah, but..." comments all over the place when discussing his achievements. It also doesn't help him that he comes straight off the back of Petter Northug's career, a very brash and divisive personality who had a very, very similar skillset to Klæbo's, and as a lot of sections of the media essentially painted Klæbo as Petter's successor in his early days, some of that divisiveness has rubbed off on people's perception of Klæbo even years down the line when he's long outgrown that comparison.
Johannes Høsflot Klæbo may or may not be the best of all time. Statistically, he's already there. But the number of things that have been stacked in his favour in time, and the undeniably cookie-cutter nature of a lot of the courses on which he's padded his win count, mean that many are reluctant to anoint him over an often overly-romanticised view of the past.