Well, we also should not forget for which team Sagan rode... when exactly did he have domestiques in his career?! He chose to ride for a team that did little to nothing to support him. He could have won a lot more races if he was riding for another team. A team that would put together a squad that can actually support him. Quickstep on the other hand is currently doing right by Evenepoel to bring in riders like Almeida, Bagioli, Vansevenant, extending Knox, etc. They try to put a roster together that can grow with Remco. Almeida was huge so far this season for Evenepoel in Algarve and Burgos.
For the longest time (until 2011) the squad was basically known as Boonen, Bettini and friends. Then they got money from Mr. Bakala and invested in classics riders and sprinters. Sure, they had the occasional climber but never really put a team around any of them. Not even for Uran who got two 2nd places at the Giro back in the day. But this time they make an effort for Evenepoel to surround him with talented riders. And when you dont have Ineos type of money that is the correct move. Build a team that gets better with higher challenges ahead. And for now they are pretty cheap. Cycling teams were struggling already but Corono might make it even worse. So who can actually build a team from scratch right now and pay a GT favorite and 7 seasoned veterans to support him?
Now lets look at Sagan: Liquigas in 2010 had the dream climbing squad of Basso, Nibali, Kreuziger, Pelizotti, Szmyd, Zaugg and Kiserlovski (just looking at that line up is still mind boggling how they got them all on the same team). Surely they would not go out of their way to support Sagan. Over the following years the climbers left but did Liquigas get support for Sagan? Except Oss not really. Then in 2015 Sagan chose to rejoin his old friends Basso, Kreuziger, Zaugg and Kiserlovski, who supported him so well at Liquigas. Oh wait ... the same silly cycle started anew. And now at Bora they not only got him Daniel Oss, but also Burghardt, wow. Sagan is one of the most talented riders of his generation but probably also the one who got the least support from his teams. I dont know how much you can blame him for that but he chose a team 3 times in a row that did not put together a squad for the races that suit him. Put Sagan on Quickstep instead of Stybar or Terpstra during the last decade and he would have more than 5 monuments instead of "just" 2. And if Viviani becomes a world beater with the leadout of Quickstep, Sagan would also have more stage wins at the Tour and not the massive amount of 2nd and 3rd places.
On the one hand I very much agree with you. But part of the Quickstep classics approach for winning is that they have multiple options - and one of them shall win. That increases the chances for the team, and, in the end, for the individual rider, to get results. But for this you have to be willing to accept that you may are not the only big option for your team. The other's are not necessarily working for you, like domestiques in a GT should do.
So for instance it might increase Sagans chances to win a race if for instance Schachmann goes with him as an equal option. Whoever is in the better position or form during the race takes his chances. But would Sagan want that? Not go to MSR as the sole leader of his team but as one option? I suppose not.
Coming back to Evenepoel I realized I start to make jokes with him as a kind of Chuck Norris.