The first few seasons were more fun.

I believe Sons of Anarchy was based on Hamlet.  Again, a lot of bodies.

Will they be read Shakespeare's 400yrs from now?  Or, bc we're doing such a good digital job preserving even our slop, will they be swamped and sink below the supposed cream?

My theory is, the top 500k will continue, with the best never really dropping out of it.

All the literature greats are in that 500k now. In a hundred years, I expect most of them to still be there.

The 'slop' just sinks, so even if in a hundred years Amazon or what it evolves into has 500 million books in it, that 500k will still be there, and probably the next 500k being it's expansion.

There's no swamp.

Just an island surrounded by an abyss which drops into a bottomless pit.

The good stuff will remain on the island for as long as people keep reading.

One of my favorite college courses was Renaissance Drama. It was in that class that I learned Hamlet was a classic revenge play--and so was Dirty Harry. (Or was it Magnum Force? It has been a few years.)

You're probably thinking of the Death Wish franchise.  Those were more straight-up vigilante revenge stories than the Dirty Harry movies.

Since the canonization process involved is Catholic, it would be the Catholic definition:

True.

Personally, it doesn't really matter to me that much.  I'm not Catholic, and what they do in Rome is their business, not mine.     Canonization of Tolkien would please me, but only because any form of praise for Tolkien pleases me.  I like it when people like the things I like.

So my original point--that we use only a very small selection of modern works to draw these conclusions, and that we have only a very small number of works, probably in many cases the best of the era, to compare them to--does seem supported by the evidence.

Sure.  This really just boils down to the "90% of everything is crap" rule, and I believe that rule to be a pretty accurate truism.  Generally speaking, the stuff that survives is the stuff that was popular in its own time, not the stuff that never caught on, because popularity results in many more copies being made, and more copies is the best insurance for long-term survival in the face of wars and natural disasters and whatnot.  I just don't like lumping the apples in with the oranges under the all-encompassing "literature" term.  Shakespeare's works, though technically literature, are more akin, in my opinion, to modern-day professional wrestling than to anything written down.  It's performative entertainment, and it makes more sense to me to compare it to other forms of performative entertainment.

I'll also add that every generation laments its own decadence and looks back to a supposed golden age in the past.

That doesn't mean they're wrong.  Empires decline and fall.  Civilizations collapse.  Nations are conquered.  Entire ethnic groups disappear from history forever.  Decadence often precedes these things.  Earth is a brutally Darwinian place, not a safe space, and societies that treat their own existence like a party instead of a contest will eventually be replaced by more serious peoples.  Some people understand this and want to prevent or at least delay the collapse, hence their complaints about decadence.

If it makes you feel better, doom prophets are rarely heeded.  For example, Ron Paul was warning about the specter of a housing bubble as early as 2001, believe it or not, but it didn't make a lick of difference in the end.  Bubble is inflated, bubble collapses, capital goes to another sector--or another country--and starts a new bubble.  Rinse and repeat until the end of time.  As it is with markets, so it is with nations, peoples, and civilizations.