There are less cruxes to the arguments then there are Crutches. The argument, again, stands on razor thin plane of narrow view and demands that are really aren't worth the time to fully address at this stage. And yes, they've been argued down before. I'm not going to glean the history of this thread and others to point it out.
And yes, COVID did impact this game, and no I mentioned it because it is a factor in recent events. Prior to that, there was a division of labor that brought new content into the fold rather than revamp assets to produce more dungeons. I mentioned tricks earlier, remember? The first was the change of design philosophy lessen extensive dungeon design to be flipped in "Hard Modes". They were far fewer in Stormblood and non-existent in Shadowbringers by design.
Let's chart that difference shall we? I won't be counting single-player instances, even though they have increased in frequency and scope through the years as well.
From ARR 31 Total dungeons 10 were Hard modes.
From Heavensward 18 Dungeons 5 Hard were modes. During this time we received Deep Dungeon and the failure that was the original Diadem.
From Stormblood 15 Dungeons 2 Hard Modes. During this time we got Heaven on High, Eureka (which Includes Baldesion Arsenal) , and 2 Ultimates.
Shadowbringers saw 13 dungeons with 0 hardmodes. We got Bozja Southern Front (+ Castrum Lacus Litore) Delubrum Reginae, Zadnor (+The Dalriada), and finally 1 Ultimate of the planned 2. (Edit, I should mention that the Trust system was implmented at this time as well, which likely added to the development cost - but that has been a gradual thing over multiple expansions since ARR.)
The redistribution of labor is plain for all to see, and arguments against current dungeon content fails to appropriately recognize or give credit to that - which fits the definition of obstinance.
Calls for more advanced, low party number was already heard in recent interviews, with Yoshi-P's patented "I can't tell you anything at this time but, look forward to the future." For weal or for woe that's usually a tell tale sign of a concern being addressed by spoilery content. I suggest you watch Asmongold/Rich's Media Tour interview if you haven't yet. Harder Low-man content was directly asked about there.
As far as my personal opinion on flash rather than substance (The title, which I've already addressed.) I maintain the stance that I disagree. Dungeon difficulty has risen through the game considerably, putting more emphasis on learning mechanics (Some of which are seen in raids.) than the dungeons before it. Barring the dungeons that were literally reused assets from 1.xx - our dungeons have been straightforward since the beginning and the emphasis has been to use them as a storytelling element on top of easy to digest grinding secessions. Viewed this way, they've been far more enjoyable both in flair and in combat over time then their previous iterations. To alter that will disrupt the flow players have long since grown comfortable with for their usual routine. Better to be putting more time-sink related options in optional content - which they have been doing.
Nothing more needs to be said here. If you're unsatisfied with the content, your time would be better spent playing other games that may closer match your desires while more content is made, rather than be arguing with people on the forum boards. FFXIV will be here when you choose to return to it.