You literally just want m+ without a timer that gaurantees rewards or acts similar to torghast where you get nothing.
If you want it to not be like torghast where deaths matter, what you really want is just normal dungeons that give you mythic level gear. Please take that view anywhere else but anywhere near wow.
There is a reason that there is a progressional level of gear vs skill/challenge. Please go play a single player game if you want the best gear handed to you for next to nothing.
There is no “strategy”. The game has been solved for a long time.
There is a certain way to do dungeons, with very miniscule changes that make it faster (like using a gate to abuse terrain walls or just literally pulling more with certain comps and hard CC bursting it down)
There is also very little different ways to do a raid boss.
For raids this has been true for MUCH longer than legion.
You either do the boss correctly or you dont.
With m+, you either do the bosses/trash correctly and in time or you don’t.
Wowhead and youtubers/streamers give you the guides before the game is even out. The dungeons are literally designed with a linear route in mind. LONG gone are the days where a dungeon like BRD or UBRS exists (and UBRS used to be a 15-man raid not a dungeon where you can do it in almost any order (and even then, it’s pretty scripted)
You do the trash to boss a.
Repeat boss B
Repeat boss C
Repeat Boss D and E if there are 4-5 bosses
You either do it in time or you don’t. Profit.
Literally all the time. Shackle and like minded hard CC is still used on the 2nd boss of Necrotic Wake whenever it’s in rotation because it literally takes a skeletal mage out of the fight completely and you don’t even have to kill it because it doesnt count towards the explosion the boss does.
Just because you aren’t doing keys high enough (or maybe you are and your team(s) are just goated) to employ their use doesnt mean it just doesnt happen.
Half the reason that MDI pulls are even possible is because hard CC is still used. Its just usually aoe hard CC like cap totem and mass grip instead of singular CC like sap, particularly because, since wrath, the PC is just too strong versus non mythic+/raid content to need CC. Blame that on people wanting the world to be safer and easier, not M+, because this was happening FAR before Legion.