But it seems to be one of those revolutions based on a single idea. And when you see it, understand it, appreciate it, there is nothing more (original) to be said.
It does not age well. There is not a semi-infinite 'fountain' of newly interesting surrealism (other than your own dreams). It can span the contextual artifact of Duchamp (you know the one), through the mild jarring of Magritte, to the impeccable fine art of Dalí, and the architecture of Gaudí, but not much more (okay maybe the magical realist writings of Gabriel García Márquez et al.).
Perhaps that is the lifespan: the urinal (1917) to '100 Years of Solitude' (1967), exactly 50 years, no more.
It's a one-trick-pony. In many cases, someone could describe a piece verbally, I would get the intention, the joke, and enjoy it, but never feel the need to see the work itself - what more could it possibly say?
Most contemporary surrealism is just cashing in on a very good old idea. It is now a cliché.
In some contexts, the more surrealist you claim to be, the more 'authentically' obscure you can make the connection to reality, the more impatiently some important gallery wants to show your work, the more big ignorant donors give to the gallery, and the higher the prices for the work. The three are connected, of course, in the boring vicious spiral of the artist-gallery-donor-speculator industrial complex (or virtuous circle if you are getting a cut).
Luckily, AI is coming to the rescue, showing that even robots dream of electric sheep, and hallucination is a common artifact of the only two intelligences we know about. There is not more in heaven and earth than are dreamt of in your human/AI philosophy. Surrealism can be generated in a mouse click, which will kick the stool out from under the fake surrealist modern art market. Good.