Are you suggesting that all time greats like Dählie and Svan are far less impressive than Kläbo because they weren't world class in an event that literally did not exist at the time?
Well, this is always the problem in setting the "GOAT". Even when you have statistical outliers, they need to be colossal outliers for it to hold as received wisdom in the way somebody like Merckx or Ali or even Gretzky have done.
The sport is so different nowadays, pure numbers are harder to use when there are far more events, a bit like counting the number of race wins as a tie-breaker in F1 greatest when there's twice as many races for the championship as there was 50 years ago. The other factor is team events. Also you have the team events to factor in. There was some discussion a few years ago in biathlon as to what the greatest championship performance by a woman was: was it Marte Olsbu Røiseland in 2020 (5 gold, 2 bronze), or Laura Dahlmeier in 2017 (5 gold, 1 silver). For my money it was Dahlmeier. Yes, Røiseland had an extra medal, but the extra medal was because there was no Single Mixed Relay in 2017 so Dahlmeier only had 6 medals available to her, so the fact Røiseland got 7 shouldn't be a factor. And then you had that
individually Røiseland had 2 gold and 2 bronze (with Norway winning all of the SMR, Mixed Relay and women's Relay adding to her total), whereas Dahlmeier had 3 gold and 1 silver (Germany then winning the Mixed Relay and the women's Relay), so to me, numerically Røiseland may have had the record number of medals, but Dahlmeier's was the greater achievement; winning "more medals in a single championship" isn't a fair comparison when Dahlmeier won a medal in every single race available to her.
So judging who the "GOAT" is is always fraught with difficulties. Klæbo is unquestionably the best of his era at this point, I feel we can say, but of all time, I'm more than a bit hesitant to accept.