My overarching point is that Splash Mountain has a monopoly on nothing.
It is not the first time that people of any age have had to experience the painful loss of a well-regarded, iconic attraction that at one point was an indispensible part of the park/resort experience, seemingly one that would be there forever (See: OG Mine Train, TOT, others).
It was not the first thrill ride (we're not talking about in relation to the rest of the world; we're talking in the context of Disney parks, in which case Matterhorn, Space, and Big Thunder all are indisputably thrill rides that all indisputably opened before Splash Mountain; and it's not as if nothing thrilling ever happened in the history of log flumes before Splash Mountain either).
It's neither the first log flume, nor the first log flume to be heavily themed, nor even the first to follow that overall progression of layout (see: Knott's).
It's not even going to be completely phased out in the world, because Tokyo's version will continue to operate indefinitely. So in that sense it is unlike attractions like Mine Train, Horizons, The Great Movie Ride, and so on where now there truly is nothing for those who loved those attractions except YouTube videos (and some of those attractions don't have that either), pictures, or recollections. Even that isn't true for Splash.
It is simply a good ride that, like many other good rides, is no longer going to be exactly what it was before.
I know this loss is particularly painful for many of you, and I cannot blame you for that; I will miss the ride too. I do, however, get tired of the continued trivializing, handwaving, and excluding of other things so that the tale can be spun that Unlike Before (if you eliminate dozens of other examples for arbitrary reasons), This Is The First Time Anything Significant Or Classic Has Closed At Disney Parks Ever, And It Is The One And Only True Source Of Good In The Universe, Splash Mountain! implication that is behind many of these sorts of posts.