Oh, I am well aware they don't intend on doing it. Was aware of that the second 2.0 dropped. 1.0 was horizontal, and while parts were extremely broken, at least it's progression had a high ceiling that only a handful of players even reached. Nobody just got their relics/darklite a couple weeks after patch and then didn't play until reset like they do now. Most of us who played it, were on 4-5 days a week trying for our speed run tokens, doing hamlet defense, running primals and trying to beat Rivenroad HM. If we weren't doing that we were trying to quad/penta meld god gear (that exploded on fail).
I think the content (aside from the repetitive formula) is great in ARR+. The problem is purely the total lack of diversion from the tomes > primals > EM Raid > HM Raid. The only thing that requires any kind of investment is perfecting the HM Dance and maybe relic which is marginally better than raid weapons if even. Ultimately, there's nothing worth investing time in and no lasting achievements. This is why people call glamour the endgame, its the only thing you will ever retain. Horizontal progression as done in the past does hit some limitations, but there is no reason it couldn't be hybridized. Couple that with variations in how endgame actually functions, take XI's Dynamis vs Salvage for example, two separate expansions, two separate endgames that were entirely different in almost every way (ignoring all the other endgame activities) and it just had a lot more depth and replay value. You weren't stuck doing the same 1-3 things every damn day for years on end.
Here's the way I see it. The dev team probably works very hard and they work smart from a business standpoint. But, they don't invest anything into original ideas or clever concepts that players will truly enjoy beyond their first few visits because hey, why waste time on something that is going to become irrelevant? That would just make bad business sense. They churn out assets for dungeons/dungeon revisions. Stick to the same mechanics, stick in a super hard boss with strict "checks" in an arena, design complex patterns of telegraph/click/phase change mechanics, sprinkle in some iLVL requirements and tomes and call it a patch. At this point, I don't see a way out of that pattern because the expectations have been set and it would crush the community to change it now.