The UFC has a real problem. Fighters keep dropping out with injuries days before events, negatively impacting the brand. People buy pay-per-view events to watch specific fights, and if those fights aren't happening, you're asking for an angry fan base. If the UFC can't consistently provide the event it promotes, the company will keep putting out bad events.
UFC needs to get their stuff together. Too many cancelled fights at the last minute, or fighters not making weight. This is making for too many bad main events, and eventually will be seen in reduced PPV buys.
The UFC has had a bad run of injuries before events, but it doesn't mean the company is putting out an inferior product. UFC 223 was missing multiple fighters and it was still an entertaining event. Injuries happen, but that doesn't mean UFC pay-per-view events aren't exciting.