I find that people simply cannot take seriously that Science would collapse down to a small fraction of its current (vast, bloated) size.
Yet there is a recent precedent for the collapse of the dominant intellectual culture: Classics.
The study of Greek and Roman culture - language, history, literature, philosophy - was the dominant intellectual activity in the West for a couple of millennia. It was the mark of A Gentleman, especially a Scholar - the most high status form of knowledge, the main subject taught at the best schools and universities.
In England, when it was the top country and culture, Classics pretty much monopolized the curriculum in the Public Schools, Grammar Schools and Oxford University (Cambridge focused on mathematics - but had plenty of Classicists too). New subjects like Science had to fight for space in the curriculum.
Right up into the mid 20th century, the most prestigious degree in England was an Oxford four year Classics degree - the premier 'qualification' for elite ruling class professions. This was detectable even as recently as thirty years ago, and the 'two cultures' debate of the late 1950s and early 1960s marked the tipping point when Science began to dominate Classics in general cultural discourse.
Classics have now dwindled to the status of a hobby, taught in few schools and never given much prominence. Most UK universities have all-but abandoned the subject - only a handful of courses at a few places can find undergraduates with any background or competence in Latin (even fewer in Greek); so most modern 'Classics' degrees are built on no foundations in three years, from zero.
Advocates of Classics find it ever harder to justify their subject as worthy of study - certainly there is no automatic deference towards it, no assumption of its superiority.
So, in the space of about 250 years, from the time of Samuel Johnson - when he was apologetic about writing in English rather than Latin and focusing his dictionary on the vernacular - until now, Classics have dwindled to insignificance in general culture.
While Classics was quietly dwindling in importance for a few hundred years (at least since Shakespeare outstripped all rivals using the vernacular) this was becoming ever more apparent from the mid 19th century, and at least as recently as the time of the great English Classics professor (and poet) Houseman (1859-1936) it looked as if the subject was on the verge of a breakthrough (using 'modern' scholarship). And of course classical scholarship has continued throughout all this, pouring out research books and scholarly articles for a dwindling audience of other scholars.
My point is that if it seems unimaginable that Science could dwindle in a few decades from dominance into insignificance then think about what happened to Classics. The signs are already there for those who look behind the hype.
Of course a scientist feels that the real importance of Classics was trivial compared with Science - the modern world depends on Science. Quite true, but then the ancient world depended on Classics, and the collapse of Classics was linked with the collapse of traditional society.
The collapse of Science is linked with the collapse of modernity - both as cause and consequence.