Than no one would get anything done. Players go into LFR with the mindset of not caring and knowing they can do nothing and still pass.
I have known players over the years who actively go into LFR with that mindset. Imagine a player now pulling 15-16K DPS in Uldir going into LFr and pulling 4K. i have seen it, they were players from my guild, and when I questioned them why basically said it was not worth the effort, they knew others would carry them.
EDIT: …Hang on if the DPS means nothing that means DPS would literally do nothing until the mechanics take place, so they would just stand there while the tanks and healers keep everyone alive just so they can do a mechanics check?
Nah, they need both, mechanics and DPS, make it so the mechanics enable DPS to hurt the boss, than make the DPS do their job and kill the boss.
Think of the second boss in Freehold, you need to do something before the fight or never pass it, but the DPS still has to kill it.
Make it so each successful mechanic debuffs the boss more and more until it dies, the more mechanics that are done the easier it is to kill, and give a limit to each person so there is not 5 players doing all mechanics, but 1 person does 5 mechanics with diminishing returns and that is it, they are done.
That is 5 people do 5 mechanics and the boss can be killed, or 18 mechanics, one from each DPS and the boss dies faster, therefore if 18 DPS do 2 mechanics each the boss can easily be killed with no issues.
Or hell, make a boss that limits how much DPS each person can do, mythic raid geared or heroic dungeon geared, they can all only do X number of DPS and if players don’t hit enough than the DPS checks will fail and you all die.
Make it mathematically impossible for LFR to be carried.
Actually this is basically what G’huun is, if the DPS or in some cases healers don’t do the mechanics it is game over, but extend it so a certain number of DPS must do the mechanics not just the same 3 people, it may work.