Player Drop Off and Accessibility/Diffculty

[Absurdity]

There absolutely is personal skill involved in savage (and ult) fights that can make meaningful changes and even save runs.

For healers, one example is if something goes wrong such as a player dying, being able to rez them while still doing mechanics means keeping the fight going and preventing total failure (this can be done even in all ultimates too because windows of time exist where a death wont wipe you).

Sure, it can be done but it depends heavily on when the death happens. If it's right before a body check there is basically nothing you can do. The other issue is that since most mechanics nowadays are designed to need exactly 8 people to solve it correctly, even if they aren't a guaranteed wipe, that one death will very likely cause additional ones since someone else is now getting hit by two mechanics.

For even more healer skill expression, knowing to top off the party and mit before rezzing a player, not tunnel visioning the moment someone dies and forgetting to keep everyone alive first. Want more? Noticing that mit is missing on at attack that may kill everyone and then adding the requisite missing amount to save the run.

True, it's one of the few remaining avenues for skill expression, but even here it's a "it depends".
Because now you're missing that cooldown for the mechanic that it was intended to cover, potentially just postponing a wipe by a few seconds.
Usually fine if you're in comms with your team, not so much when you're dealing with PF.