The dream of Mythic is basically dead... Frost Interview with Yoshida

[Rilifane]

World of Warcraft Mythic is what it is and what those who look for it tend to enjoy because of the weekly rotating affixes and how the difficulty spikes can be partially controlled via keys, but more then that; it's become a part of Warcraft's underbelly black-market where players sell key runs for gold and RMT.

RMT and black market was never the primary appeal of mythic+ nor is it exclusive for it. It's a side effect of not being able to prevent such things for any content of that sort; be it raids, mythic+, PvP or achievements.
A company cannot control who you form a party with - there is literally zero difference for the game between a premade made of a buyer and a couple of run sellers and a premade made of friends. You can prohibit account sharing all you want, it's always possible to bypass it somehow.
Just look at FFXIV PFs and you'll see how much of a mythic+ thing it is.

There is a whole subculture of personalities and a eSports league with real cash prizes on the line connected to Mythic 4-man dungeon's. That's not something another game can easily mimic or try to partially incorporate with hopes of attracting the same sort of personalities and evoke the same type of successes and failures.

Once again, that wasn't the primary appeal for Mythic+ either nor is it essential for it to function. It's a side effect of the generally competetive nature of WoW and its players. People even kept asking for eSports events for pet battles.

I'm glad we aren't getting anything like that in FFXIV, but I don't believe that it should excuse them from at least trying to innovate and perhaps look at what made Mythic resonate with Warcraft players and say: "Alright, so we know the whole system itself wouldn't work in our game, but what about this small little piece here? Perhaps that could work somewhere in our game."

Exactly, we look at Mythic+ and see that pretty much the whole system would work here. RMT and eSports are not part of the system itself, they are either unavoidable or a side effect of the community and its followers.
The system itself only includes (or would include): light party content with scaling difficulty for players of various skills levels, added randomness through something (Affixes or something else), added pressure through additional rewards being tied to a timer.
RMT/ gill sell runs will inevitably happen as with everything that people want but don't want to get themselves.
eSports will very likely not happen and it doesn't make a difference for the system itself nor will it matter. Mythic+ was immensly popular before either RMT or eSports really hit.

FFXIV sorely lacks midcore content that ideally starts with the difficulty catching the casual crowd and ending with a difficulty that's meant for skilled players that are into challenges and optimization.
FFXIV escpecially lacks such content for light parties.
With the dps meta firmly in place for years it would even work quite well with the current system; it would teach bit by bit how it feels to push for more and more efficiency, something you're never confronted with until you hit (to an extend) ex and savage.