Same thing with Coils. Even T1 used to be a whole ordeal. You'd be surprised how many people back then were so eager to enter Coil raiding only to find themselves unable to enter the front door (so nicely guarded by ADS). At that time, 1 High Voltage meant a wipe. Nowadays, you can speedrun T1 with 1 Tank, get hit with 2-3 High Voltages, skip the trash mobs, and burn the snakes without even feeding slimes.

It is true players are missing out on experiences. But that's just how the game is progressing. With every nerf and gear upgrade, old content gets changed and will never be the same.
The only solution would be to stop introducing nerfs and put strict ilvl Syncs on every Duty.

But then you'd have more people crying that the content is too hard. See that thread about the New Trial being too hard? What a joke. Do you want to see more of those?
The idea is that Square-Enix wants more players (read: lower skill capability) to able to complete certain content within certain timeframes.
So they allow overgearing and introduce nerfs here and there when they deem fit. Look at Pharos Sirius: that dungeon had to be nerfed THREE times before people were satisfied with it's difficulty.

People WILL unsubscribe if they can't clear the content that they want to. I should know because I did it myself last year. I took a ~3 month break because I maxed out on my Soldiery gear but was still unable to clear T5 and Titan EX, which had me really upset and pulling my hair out. But when I came back and resubscribed there was a new Tome available and much stronger gear, which I collected to make myself stronger and was finally able to beat those instances. Did I miss out on experiences? Sure I did. Big shout out to the people who were able to clear T5 and Titan EX in i90 gear. Even so, I was still very satisfied with my clears whether I was overgeared or not.

The point I'm trying to make is that with each new content addition, there will be new things to struggle on, work on, and grow on. Let's just face it: Garuda HM is "old content". And Square-Enix doesn't want that particular instance to be a stumbling block or they'd do something about it being too easy. Being an older and more experienced player, it's nice to think back and reminisce on the difficulties we've overcome. But know that future challenges await, and people won't be gliding through easy mode and getting carried throughout their whole gameplay experience.