Every time you start getting excited after a series of quick finishes or action-packed fights like Jason Knight vs Jim Alers (one of recent prelim fights), remind yourself that you're about to see sloppy kickboxing matches or grinding affairs on the main card, and that pattern is rarely broken. Occasionally it goes the other way around: prelims are full of running in circles and grinding and main card delivers (like UFC 189). But very few cards can keep viewers excited all the way through. And sometimes the entire card sucks.
It really just depends.. There were tons of great main cards just in the last calendar year... It wasn't until 200 that things have been out of whack tbh