You have read me talking about this here and there on replies of other threads but it's time to put it clearly as the main topic of discussion for community-leaders feedback; I remember fondly the time I suggested to the devs to replace the 10man and 25man sub-gametypes with a new ~18-man-only raid; it's time for a new major update to the PvE super-gametype.
Section A: The WHY:
1) The trash of 5mans are just ..trashy most of the time (it's in the name players gave to them); they do not deserve being counted; they result to flavor-of-the-month specs cheesing it with basic AOE and basic single-target and making the whole 5man gametype a chaotic silly thing.
2) PvE of Raiding has an elephant in the room: 5mans of mythic+ clearly have something superior than raiding; the timer clearly has something to do with it; we must find a way to make raiding into Raiding+ but without ruining it for anyone (either casual or professional).
3) PvE in whole and Especially raiding must have downtimes; people want to relax once in a while; Raiding has that extremely excessively at its downtimes (leading even casuals hating they have to spend so much time inside instances) but mythic+ is too stressful.
Section B: The WHAT to do about it:
1) Do not count any trash-time or any out-of-combat time; if you do count a trash group: make sure it's well-designed like a boss; out of combat time is perfect for relaxation to be dropped and nobody wants to reward anyone for being good at going up stairs.
2) Do the exact same for raiding / 20mans; there is absolutely no reason anymore to avoid turning it into raiding+; you knew from the start the main reason you avoided it (but you wanted it) is the extra stress of 5man-mythic+ and now this is gone.
3) Start from an extremely easily-done level for Raiding; this will keep it perfect for casuals and easier than normal initially; it will leave the Professionals able to reach their absolute limits at the same time.
Section C: " But what about the CASUALs and the PROs and the LEGACY designs":
1) The casuals are covered perfectly when it's starting from an easier-than-normal difficulty; also some casuals do want a time-limit in reality; don't they hate it if they have to spend their entire week in front of a difficult boss (they want an excuse to quit to their raid leader for the week).
2) The professionals are covered the most of all; there will never be a limit; also they will show their skill clearly because trashy-trash are not counted and flavor-of-the month cheese-AOE(or ST) are not able to contaminate the competition.
3) Legacy designs can exist as special events; or even in parallel; but why have suboptimal designs as the main thing: you know raiding is missing something after mythic+ was introduced and: you know mythic+ is lacking more order.