In many ways all you really need is an actual learning curve. something that simple would go a long way to fixing many of the issues i beleive. some basic elements of challenge even in the msq and all content.
it would also add credibility to the story in some ways.. it's a total scene buster when the story does everything it can to paint a grim scenario or dark situation all hope is lost. the threat is tooo large..... omg the world is doomed.. and you roflstomp it without any clue whatthe hell is going on...
there's battles in the MSQ for example that practically impossible to fail. most memorable for me personally is one in 4.0 where you attack the bridge and mnaagoglamours the flag... got a knock at my door some couriers turned up to deliver some furniture. put my controller down went and dealt with that.. came back 10 maybe 15 minutes later expecting to be dead and nope, id won the fight.... i was literally afk auto attacking whatever i was engaged to when the door went. and still beat it....
a decent learning curve would also naturally kind of tier the duty finder in some sense. because players would need to be progressing up that curve in order to unlock the next piece of content rather than traveling along a long horizontal line that might have 1 or 2 slight hiccups along the way. and it remove a lot of the problems people have withparty finder groups as well as anyone who was able to proceed far enough to unlock a piece of content would at least have a minimum ability to participate.
basically what the game should do is help players rise up to the content or challenges in order to help them grow and develop. but what the game does is just bring every piece of content down to the lowest possible level. which causes problems because basically if your skilled enough to clear sastasha you're skilled enough to unlock ex trials and savage raids... because the learning curve is a horizontal line...