Most of the Tour versions the last 15 years would have only been worse with more ITT and harder mountain stages. Contador, Froome, Nibali, Wiggins and Thomas would just have been more superior than the acutally were.
Ok, so: The Tours of the last 15 years
Sastre 2008- already enough ITT, I agree that more mountains would not make it better
Contador 2009- agreed
Contador/Schleck 2010- you‘re probably right, although having more ITT would make Menchov more of a threat, perhaps Schleck with harder mountains would win (might not be better, but I don‘t think it would be worse)
Evans 2011- meh, more ITT would probably make the Schlecks attack in the Pyrenees, I don‘t know how it would affect the Alps, it would have been a different race, not clear if for better or for worse
Wiggins 2012- already had enough TT, more mountains might tire Wiggo out leading to more Sky infighting. He would definitely not be more dominant on a perfect route
Froome 2013- Froome struggled on the tougher stages and in the last week, maybe more TT would have killed off the GC fight early, but remember that Quintana and Purito were forced to attack for podium places anyway
Nibali 2014- I don‘t think it would have mattered, it might have been more spectacular even
Froome 2015- Froome would have gained a lot from the ITTs, I‘m not sure Quintana would have kept trying,but remember Froome was only the strongest on the Unipuerto mountain stage, it might have been similarly interesting
Froome 2016- nothing ever happened in the mountains, it could only be better
Froome 2017- awful route, awful race, Froome was not dominant on the tougher mountain stages, Sky could have strangled the race even more if Froome had gained more from longer time trials but Froome was never the strongest on the Tour‘s queen stage: could be worse, could be better
Thomas 2018- This one actually had decent mountain stages, but remember that
more dominance≠more boring The race might’ve been different
Bernal 2019- a lot better with more TT and tougher mountains: Thomas would struggle to maintain his lead while the others would have to make up loads of time, Ineos would not be able to control it, who knows what Alaphilippe‘s role would’ve been
Pogačar 2020- the race was only saved by the plot twist in the end, maybe Pog could‘ve had another miracle performance in him with another ITT, probably better
Pogačar 2021- Pog killed off the race on two stages in awful weather but I don‘t see why a tougher race would make it worse
Vingegaard 2022- yeah, it would probably not be as amazing, but we know the final ITT was affected by recovery- another ITT might have put Pogačar closer- also: the top teams would probably have lacked the numbers to control a tougher version of the Pyrenees
Conclusion: I think the idea that most years would be worse is not clearly true. Racing might have been different but I also think that dominance on a tougher route would not be worse;yet this is just my personal opinion and I‘m really extreme when it comes to the spectacle vs. suspense question: Using the football metaphor I might even take a 7-2 over a 2-1.