So we have a situation where the game design is built around rewarding the fastest clears but the devs want to create a more challenging game, apparently, that you can’t clear quickly.
To fix this is to overhaul, entirely, PVE.
If you make nodes clearable once and done, you need to build some kind of measure of success in (losing less health or what have you) and probably assign a star rating to your play (many many games do this, the DC match 3 which is now shut down did this). To me that would be the best way to approach this change, not by leaving in place the same game design.
But instead they are just tweaking things. Maybe from one perspective that makes sense but it just feels incoherent to players and frustrating when the game locks some rewards behind clears you now can’t do.
I don’t really think they can overhaul the game successfully to create a new style of play with new incentives and new ways to evaluate play, just due to code mess and whatever. But if you wanted to push the game into that model the correct way would be to make whole new event in that style, something like a 7 day event with nodes once a day or something. Phase it in, perfect it as much as possible, push it into PVE with new PVEs or adapting old ones. (or just make Tower play that way for now)
I do not know if the game economy and currencies etc support a model like that tbh. The DC game had a mess of various currencies and things you could level up and you’d collect this or that thing to make better gear. etc etc. Our game is blissfully simple. Roster toons, collect covers, use iso to level up until you champ, add more covers. The gear is also simple, just level up the support and use risk to level it up.
TLDR: I do not think the base game design or economy supports their project of slow hard clears you cannot fully do/collect the presented rewards and possible points. It explicitly rewards the opposite. They have broken the loop of play grindy, collect stuff, incrementally improve and do better.
BUT the old guys kind of did that already by making new toons not matter due to OP meta. I do not envy the devs trying to keep the plates spinning and somehow incentivize more spending.
Unless their goal is pushing in new toons that are faster or redesigning the whole PVE mode in the very near future they have created an environment where the players will just en masse feel frustrated by now being unable to accomplish goals the game has presented to them. They have not modified reward structures or added new rewards (outside Heroic nodes) in any way to make up for this. This is why people are getting fed up and engaging less.