Regarding the contract numbers (& whether they're correct, i.e. the number remains unchanged since his extension last year so we don't know for sure) I'd suggest some performance bonuses are probably not taken into account. Jumbo are also a sort of "family" unit as well with a close-knit environment for their riders (& they're not rich like UAE or Ineos), so raw numbers don't tell the full picture.
Their budget would change a bit after someone on the squad wins the Tour. Sagan as a huge fan draw is the outlier in that upper echelon but almost all of the other top 20 guys have shown well publicized success in GTs; specifically in France. It's where the sponsors and broadcast is.
Does he deserve to be in the top 5 wage earners? I think so, but I'm prejudiced by his overall talent that, hopefully will be rewarded by a win in July.
He's the best rider to have never won the Tour de France, IMO. His level in 2019, 2020 & 2021 would have been enough to win it in quite a few of the previous editions against the riders who won it at the time. I include Froome in that as well, who I believe at his peak is inferior to peak Roglic (Froome would perhaps match the TT, but would lose mountain sprints against Roglic every time).
Still, I don't think history is written yet & I don't believe the Roglic story is anywhere near over, i.e. that elusive Tour de France win won't define his career (or at least shouldn't) but we do know he's going to go & fight like crazy for it in July. From a spectator's standpoint it's going to be amazing IMO because Roglic won't be interested in another podium, so he'll go all in, tactically as well (a long distance solo attack if necessary).
And that "fight" will also define how people remember him (a bit like Johan Cruyff's Netherland's football team in the 1970's, i.e. win or lose, the performance made them legendary). Roglic can do the same versus Pogacar (who really is at this moment one of the best cyclists in history).