Just throwing my two cents in here: Yoshi-P and team have talked about some of the complications they've faced with workload for the past while. Updating the graphics engine has been quite the hefty undertaking. Converting every MSQ dungeon in the game for Duty Support ended up being significantly more work than they initially expected. Covid hit them hard, as it did for many companies -- and while I realize the worst of that was a while back, delays like that can have a ripple effect that pushes back content long after the fact. They're also working on porting the game for Xbox, updating the dye system, and they're adding female hrothgar. And... well, let's not pretend developing FFXVI didn't drain resources from the team as well.
You can argue some of these are valid or invalid as excuses, but I don't bring them up as excuses, I bring them up to point out that they're all one-time things that cease to put extra demands on their workload once they are finished. Things like Duty Support, the graphics update, new race, dye channel update, the Xbox launch, are all investments that will make the game better across the board. Once Dawntrail is out, they won't have to worry about any of that stuff, it'll already be integrated. Whatever you can say regarding Endwalker's patch content lull, what's done is done, and I think we have reason to believe things will improve with Dawntrail, on onward.
Regarding the cash shop, well, I can't defend that. I hate it. I bought the game. I bought the expansions. I pay my subscription fee. I don't like that they ask for more money on top of that, and some of the prices are unreasonable to boot. I don't even really believe the claim that "cash shop money goes back into supporting FFXIV." It may be technically true, but there's probably something scummy going on behind the scenes, like the CEO looks at FFXIV's cash shop revenue for the year and says "Great, we can fund FFXIV that much less next year, because you're making it up in cash shop sales."
It's not that everything in the cash shop would have been put in the game for free, it's that the developers and designers only have time to make X amount of stuff in a day. Their workload is divided between making game-earnable things, and making cash shop things. Did Square Enix simply hire more staff to account for this, so that the regular flow of free game-earnable content did not lessen in the slightest? We don't know, but frankly I would find it hard to believe.
On the other hand, many cash shop items were available for free during limited-time holiday events. In most MMOs, holidays come back every year and if you miss something you can probably get it next year. Not so for FFXIV, they just take it away forever, and if you want it then you can buy it with real money. Setting aside the subject of the items themselves, even the quest content disappears and can never be played again. As a result, they put very little effort into making holiday content because it is so brief and disposable. Holidays in FFXIV are just vectors for future cash shop items, and that's a huge part of why they are cursed to always be terrible.