You can have both, I'm also not saying I have all the answers, I'm not a game designer but here's my attempt at an example. Before that though, I'm not only considering one aspect, I never specified as I was simply saying generally an area where you could improve something not how it would be implemented. I do believe you could have both, something more challenging while being more recoverable. You also wouldn't have to ease up the checks, you could also try to redesign them to allow the fight to go on even if you fail them but give a punishment for doing so that doesn't end in a wipe. I'll try my best to give an example of such.

Here goes:
OK so you have a DPS check, you need to pop a shield on the boss before X amount of time. if you don't it blows up pretty much killing you all. OK how about if in place of that, failing the check now places rotating aoe's that do masive damage/outright kill anyone caught in them, theses will remain for the rest of the fight, you've not failed but you've got one more thing to worry about.
Lets' try a healing check next, one party member is dropped to low hp with a healing debuff, you've got X time to heal them up or the debuff pops and wipes you, instead failing this suddenly reduced the arena by 1/3 again you've not failed but now you've a lot less space to work with and even less if you failed the above dps check. Mechanics after this could still wipe you for failing them, as the fights given you your chances and recovery and any further failing is game over.

Now you could argue that people will just fail both and win anyway, "Why bother dealing with theses if we can just win and ignore them?" That's true, but at the same time if designed right, you'd be risking a lot by letting theses checks fail and it becomes more a choice, what's best for you? Letting them fail to just dps the boss/rezing someone/deal with some other mechanic that might also be going on. Or play the checks to keep the mechanics more manageable, The extra recovery would be nice but it's still hard and still can be danced perfectly if that's the play style that works for you. Again someone will always do what's easier but that happens now, so, as long as this could be done without lowering the difficulty nothing would chance there.

I never said this was the right way or best way to fix the issue, just voiced it as an idea, feel free to rip the above example apart, it seems like if balanced it could work but I could be very wrong, if I am I apologise for wasting your time with it.