There are SOOOOOO many ticky tacky rules they have to follow. The NFL has TWEAKED things TO DEATH. Some for Safety reasons, others,,I have NO idea why?? Also.....And I try to remember this....My Late Ex Brother In Law (GREAT guy) Reffed High School football games and he told me just how difficult it was to know where you were on the field, watch a broad area closely and all while trying to NOT get pummeled by very fast moving players. But with that said, Officiating HAS gone way down hill.
Personally, I wish they'd get rid of Instant Replay and go back to the rules of the 1970s/ to mid 80s. We still see soooooo many missed Replay calls. And with all the added rules...... Watch ANY game from the 70s / early 80s on Youtube and you MIGHT see 5-7 flags the ENTIRE game! These days???? You can easily see that on one drive! And Replay......Very few times do you see it needed. The flow of the game was SO much better.