You never really see boxing kill its stars. They have their own serious problems but one thing that they handle rather well is understanding that elite fighters are just Human. They have X number of title fights, wars, weight cuts and cycles of PEDs in them. At some point one of these is going to flip to a Y and that investment is largely over.
The UFC sold to WME based on that investment concept back when all the big stars were active but at no point did they protect them. They do cheat in some instances but it's self serving. It's never about the longevity of the fighter. It's more about saving that card with a few exceptions. PRIDE probably handled it better. They would feed some of their top names more average fighters on purpose to build their names and then the protection is pulled for title fights. They took a page out of boxing and it worked. To this day those guys with big names who got put over by lesser fighters are legends.
Joe Sixpack doesn't need to know/understand this. That's the promoters job so they can milk these guys for 10-20 years. The UFC? Let us feed you to our newest hot contender. You kill contender? Do we want you as champ or think we can sell it? No? We feed you next contender. You kill that contender lets us feed you a stylistic nightmare you are unlikely to beat. They did it to Silva, Aldo, Ronda and Joanna. Silva managed to survive his first bad matchup in the final round in a fight he was losing and at least he was still champ when that happened so it's looked on more favorably. Ignoring Max, Aldo ate two contenders before getting his bad matchup and losing to Volk in a depressing display. The Max fights were worse but Max at least gave Aldo a chance. Ronda was given one of the worst matchups of them all and it ended predictably and has retired. Ignoring Rose, Joanna beat Tecia in a fight most people forgot ever happened but you sometimes have to fight like that to win vs a style of fighter who just beat you twice and who arguably beat the person who just beat you... twice.
Management are predominantly 30 to mid 40 corporate social climbing fuckboys in 25-50k suits, some of whom enjoy sexually assaulting the vast talent pool, and they are about to launch their IPO. They might actually be egotistical enough to put some fighters names down when talking about the future and growth. I would love to see that page.
They bought into the whole hype train based on the fighters names but they never treated it like boxing. They could but they won't. There's nothing stopping them from having any big name fight cans to build them up. They did it for Valentina. Just look at her when she wins. The absolute unashamed ego as she is covered in blood. Exactly what she needed priming her for an eventual fall but even that was mostly a one off.
TLDR: People assume the UFC and WME might actually know what they are doing with some of the elite matchups. The fact that PRIDE existed and Boxing exists yet the biggest stars get regularly destroyed proves they are just 40 somethings mashing their GI-Joes together for billions of dollars while the fighters make shit.
