You know, I've repeatedly been all in on those "meh, why are all the riders so god damn passive" discussions but this time, as much as I hate to say it, I kinda get why everyone is doing exactly what they are doing.
Roglic is leading the race and is the best TT'er among the gc contenders. Moreover his biggest strength usually is his explosiveness towards the end of climbs which makes, controlling the race until the final few hundred meters not just the best tactic to not lose time but actually also the best tacitic to gain time. At least on Pogacar that is and I don't think there is a serious danger from anyone else anyway. He has the team to race how he prefers it so they do.
Pogacar is the one who should probably be the main aggressor. He seems to climb at least as well as Roglic and isn't too far down in the gc. Yet the guy is 21, he has no team support in the mountains whatsoever and attacking that Jumbo train might be a legit tactic to eliminate some other 2nd tier contenders, but it's an extremely risky one against the guy with the strongest team, especially on a climb like the Grand Colombier. I think Pogacar was basically relying on Ineos to make the race hard for him but we all know how that turned out.
And all those guys behind, sure they could have attacked, someone like Contador, Nibali or Froome in their position even might have attacked, but they aren't Contador, Nibali or Froome. The 2nd highest rider in the gc with a GT win is Quintana, over 5 minutes down (random side fact here, there is one guy with a gt win on the first 9 spots and 5 guys with gt wins on the next 8. That seems weird), some of those guys don't even have gt podiums. Those are not the sort of riders you expect to risk it all on a stage like this. Also, while usually I hate the whole idea of "waiting for a better moment to attack", because most of the time no better moment arises, this time it might be merited. Let's take Landa as an example. He knows, he could attack here, but he's most likely gonna get reeled it by Dumoulin and lose more time later on. He could also wait for the Col de la Loze where, even if JV are strong again, they can hardly control the race even more than they did here, and the gaps around the 3rd place are so small that one good stage would be enough to overtake everyone in front of him anyway. That said, if he loses time here, it might not.
Now of course, riders who only sit behind a train and don't take risks won't exactly become fan favorites but then nobody is talking about Adam Yates' legendary, aggressive riding style right now either and I doubt an attack by Landa/Uran/Mas/... would have ended any different than his. Let's face it, even Contador usually had better set ups for his attacks, at least for the ones we remember.