Ok we get you like Conor, we get that you think you are the world's expert in the UFC fighters, but your enthusiasm is making you get carried away. No one is actually 'hating' Conor here ( he's actually quite a charming man) but you are taking your opinion as being a fact and it's not, it's an opinion.
Look, you can't last against a school girl, you are a beginner so I don't actually think your opinion is that strong on this.
No they don't necessaraily have the best they have the most entertaining, the most talked about, the most fighters who sell tickets. The UFC is a business it is about making money. Conor sells tickets, he has a lot of haters who will buy tickets to see him beaten ( the UFC knows this and will match him accordingly, either to build him up or knock him down), he has a lot of supporters who will also buy tickets, for the UFC it's win win, they make money, for the fighters not so much. They also don't pay nearly as much as you think, there's more conditions than you think as well. It remains a world wide brand name and people want to fight on their shows but it's rapidly turning into how boxing is these days. How many people who have fought in the UFC can you call friends btw? I think you are looking at this from a fanboy point of view so aren't seeing behind the hype and show business.
Any fighter is only as good as their last fight, any fighter can be beaten, fighting is a strange game and relies on a lot of things, a fighter will train, do their conditioning, get their tactics sorted and yet it can all go pear shaped in the fight for reasons they never thought of. It depends how well they can 'adapt and overcome', even the best can't always, it is as had been said in the past it's a game of physical chess, even a weaker opponent can beat you nothing is certain, that's what makes it exciting to watch.