personal parser only, here is the issue. Player X is a NIN and he consistently does 800 DPS now, it is released, he makes some changes and now does 1000 DPS. He sees he improved and stays doing same number consistently and thinks he is fine. What he does not know is he should be doing 1400 or more. Without seeing the rest of your groups numbers too, or some comparison to others on the same job in the same instance (within a similar ilv too i guess) just seeing the numbers is not enough.

when raiding as a PS4 player, I absolutely hate it when the PC members of my static are not parsing and giving numbers out consistently because I can make every tweak and change in the world and gain 2-5% dps (or maybe even more) and not really be able to tell at all on any individual run. Add in that multiple people are making changes and your DPS may go up but someone else tried somethign that was not good and hurt their dps to a net wash, you both may stay with the new way or may both go back, or worst case I go back and they stay with the new way and your raid dps just went down. When your enraging at 10% on vortexer in a6s, unless you have numbers for each pull to see who is doing what and how player X's DPS changes as they try to make an adjustment to rotations around fights to know if it actually helped or not, you waste soo much time not knowing.

No matter how you look at it, these numbers are a vital part to doing any relevant end game content, and anyone who thinks they are not needed and can tell without them are lieing to themselves and are likely just afraid they may find out they have been wrong about there play all along.