I agree their presence tends to make races a tad boring if there is nobody to rival them, but I still very much prefer genuinely great riders making memorable performances over a bunch of meh riders having close but forgettable races. I absolutely think men's pro cycling is currently more enjoyable than towards the end of the 2010's when the greats of the previous era, guys like Froome, Nibali, Valverde, Cancellara, Contador, Gilbert were either retiring or losing a bit of their former strength. That just let to lots of races being won by riders I feel kinda indifferent about (Which QS rider will win by attacking a big group and nobody willing to chase next???) or races still being won by the same great but now old riders, who were missing a lot of their former spark (stuff like Froome in the 2017 Tour).
Those races were often close and unpredictable, but I didn't particularly enjoy Valverde winning his 600th sprint out of a small group, Froome winning the Tour less than a minute in front of Uran, Thomas becoming the #1 gc threat in the world, or Terpstra and GVA winning classics because everyone else was obsessed with Sagan's backwheel.
Evenepoel winning yesterday wasn't very exciting, but was it less exciting than most LBL editions of the late 2010's? I really don't think so. Right now at least I know that when two of the big 6 are riding, I'm going to see a clash of two titans. And that's something I feel we currently aren't really appreciating.