Imagine this:

Lesnar drops out of the Reigns match, tripping over a cord in the back. They offer it to AJ Styles, who takes it on short notice, but is pulled out due to injury. They turn to the Miz, as his opponents got injured, but the Miz wants a million dollars to fill in against Reigns, and the WWE turns to Bryan. Bryan hadn't been wrestling for long enough, and the guys in charge of the arena wouldn't let him take the match, so they turn to Kevin Owens, who faces Reigns on 1 day's notice. They turn to the Miz to replace Owens in the tag match, but Miz likes Bryan too much and won't wrestle him, so the match is scrapped. And finally, it turned out that AJ dropped out because he didn't look right to the people in charge, who didn't even bother to bring in a doctor, so he dropped out for no good reason, and two matches are gone.

This is what happened to UFC 223. Never forget.