The Olympics has never in history been “the best of the best,” nor was it designed or intended to be. It’s an exercise in international relations, first and foremost. Each nations brings the alloted number of their best athletes. And they all commune together peacefully, and after the competition they shake hands and part friends. Or at least that’s the idea.
Before professionals were allowed to compete, the Olympics comprised of each nation’s best wealthy amateurs, since the po folks couldn’t afford the training, equipment and travel (except for a few that found wealthy patrons.) However, as time marched on, more of the audience was starting to see through the sporting hype. And then and then, and the decision was finally made to bring the true best of each country, regardless of pro status.
I think of it as like a big international picnic, with sporting events … 
NBC would like sports fans to think the Olympics is worth watching for sport, cuz if the international happiness were the big focus over and above the sports, I think the audience would be small.
But again and again incidents like the gymnastics qualifiers and the old figure-skating scoring scandals kind of peel back the pure-sports facade.
However … no matter how many additional riders would have been on course today to truly showcase the best in the world, the XC today was a sterling view of some of the best riding in the world. It was inspiring. Loved it! 
The best-of-the-best competitions are available every year in multiple international sporting venues that are open to all qualifiers. Badminton is an example.