I’ve seen many of these threads pop up in the past, and this one isn’t special even with commentary from a designer. A trap many of them fall into is that the issues discussed in them are improperly framed and discussed at surface level. But that’s the nature of of the almighty “buzzword” mentality that you warn us about- arguing things through a cursory look at the issues. If progression is the issue, then the purpose and mechanics of progression needs to be acknowledged, not simply how one feels about it. This extends past issues of pacing you bring up as well.
Put simply, the progressions system is pedantic and uninteresting, but it depends on how you frame it. If we’re talking about progression in relation to content, the most prevalent issue with progression occurs throughout the game and not just with ascended gear. The issue is that the vertical progression does not break the monotony of gameplay. This is apparent after obtaining max level for all trait points and skills but for some professions even level 30 or 60 is pushing it. After the optimal skill rotation and stats combination are figured out progression afterwards doesn’t open up meaningful or engaging gameplay options or challenges (and it rarely even mattes what you use in this game for better or worse). The stat progression simply increases the numbers scaling. It’s an issue with build variety as well; almost everything is a variation of the same type of gameplay as in the early levels which are already arguable rather monotonous to begin with. The numbers move slightly different is all. I’d say that the combat, skill design, a enemy design are the core of this issue. I’m sure a designer could further elaborate on it, if he or she knows what he’s talking about.
What has ascended gear added to the content? Bigger numbers to the very same type of gameplay. Absolutely unnecessary, and ironically enough it’s even argued that way from the sides either supporting or indifferent about their implementation.
If we’re framing the issue in terms of acquisition as you are, then the method of delivery is simply uninteresting. It’s predictable and it forces players to form schedules simply to acquire it in a reasonable amount of time. If we’re to draw comparisons between this game and the loot-centric Diablo series (inb4 different game and genre so even similar things are irrelevant!), the loot system is not unlike Diablo 3, where, due to the phasing as stat balance, only the highest tier of loot in the highest game mode is relevant. This has the added effect of phasing out certain maps, making them irrelevant NPC/Auction House fodder. Compare to, say, Diablo 2 where loot is relevant due to the item upgrading system or even GW1 where all loot after the tutorial levels are fully functional. Even lowest tier drops in either of those games can be useful, but there’s still a random rarity system to spice up the drops.
If we’re talking about the gear itself, then, as stated before, the gear has added little more than stats.