Nothing against your post, but I found funny that longer efforts on the mountains are perceived as modern cycling, when it's the opposite. Muritos and wall climbs are modern cycling, GC was traditionally built on long and sustained efforts on multi mountain stages and really long TTs.
Regarding Roglic time will tell. I personally think it's rather clear he is at least a level (or two) below his old self. If I were him I would have targeted the record at the Vuelta, which has always been the GT best suited to his strenghts and the one he is more likely to win, but with he earned the status to choose his calendar a long time ago.
There was definitely a solid period in the 2010s and what not where a lot of climbs were done with very negative splits so where they would go under the max until the final 1-5km of the climb.
Beyond what everyone believes has happened to our favorite stomper and his fast twitch fibers (abducted by aliens and replaced by a clone is a possibility we can't discount), his coach Marc Lamberts said before the Giro that he's training specifically for longer efforts now - not punchiness. We covered this topic a couple of months ago, i.e. he's evolved from an Alaphilippe type who excelled on shorter efforts to a climber type who can now adapt to the needs of modern cycling - which is going faster and harder on longer climbs than he used to.
And guess what? This Tour has a load of longer effort climbing later in the race, i.e. 40 minute+ grinds. So maybe he is totally washed and kaput but there is a valid explanation here (aka his aforementioned training) and until he's shown his hand in the mountains (or hasn't because he doesn't have it), I'll reserve judgement.
It's also a periodization thing. The kick was alright in Catalunya, especially on Montjuic he just torched everyone on a sub 2 minute hill doing a consistent pace. But then he did specific training for the Giro, which is mostly endurance and long work (my boy really wanted that Finestre FTP test).
And now he's had to recover first from his Giro before doing work for the Tour. He's probably coming in a little slow, like last year, when he got dropped silly on basically his favorite hill and then by stage 11 he was already stomping away from Evenepoel on short steep sections.
ALso remember than in 2022 he was nowhere to be found on that stage 4 hill and then he got 3rd on PDBF a broken back and dislocated shoulder later.