I'm on the fence on all of this. I have downed all the content in game already.
I kinda see the OP's argument on keeping difficulty the same while also understanding the need to open up the content to newer players.
Their is a sense of accomplishment that comes with downing un-nerfed content but on the same token, the persons who have not done it, why would they care otherwise? They have not done the content anyway so to them everything would be new.
Think about it this way, when OoBG had first T5 video, people didn't rise to the challenge to just grind out all the same the way they did. Nope, majority of people watched their video and guess what, many people now mimic their T5 ritual while there's several other methods.
I guess what im trying to say is, pre-nerfed content is only an issue for the people who feel accomplishment for tackling said pre-nerfed content with no assistance, otherwise no one should watch videos of successful attempts because in essence that would also be making the game easier.
Do I think some extremes should remain unchanged? Yes, but with some restraint.
I personally think Titan Extreme is one of the best designed fights, absent of the lag some players experience, because honestly it's some of the most advanced content at current you can get given the play style of our current battle system. In such, I'd hate to see it nerfed in essence, but an echo buff, may not be so bad. Its rare that people fail Titan Ex, because they couldn't do enough damage (with everyone up/no weakness) but more because of failure at dodging so what would, an echo buff do for them if they still can't dodge lol
Same thing with Ifrit EX, if tanks don't swap properly if people aren't dodging correctly or healers are flubbing on healing or searing wind, again an echo buff probably wouldn't add too much to the mix and if nails are actually breaking quicker due to higher DPS, this actually may make it more difficult.
Garuda EX stands to be the only primal that can actually be made easier via echo buff, because you essentially make it easier to tank with more HP and go through rotations faster with higher DPS overall.
Other things like ADS, High Voltage being esuna-able, I actually agree with. It makes no sense to reflect the urgency of a High Voltage being silenced, but give no option to recover properly if it does happen. In essence that's forcing a party setup to include two silencing classes.
This is also really damn true too.