Unless I haven’t found where to look yet, the literature on this period seems to lack good expositions which lay out the case in defense of the traditional social system that the philosophes mocked and rejected. Jonathan Israel references now obscure books written by the philosophes’ contemporaries which respond to the Enlightenment’s propaganda with anti-philosophie, but because these men, mostly Catholic clergymen and theologians, allegedly lost the historical argument to the philosophes, lots of luck finding accessible versions of that literature now, and in English translation.
Your comment has brought up a possibility that had never occurred to me before: perhaps one of the weaknesses of the anti-philosophes is that they felt obliged to defend their particular brand of traditionalism (Christian traditionalism) and therefore didn’t have the cognizance to give the best general defense for traditionalism as such. Basically, the Enlightenment thinkers got to strawman traditionalism as Christian traditionalism, whereas in the least convenient possible world they would have had to argue against the 18th century equivalents of our neoreactionaries—which, even if you don’t totally buy into their arguments, you have to at least admit that they would have made for more formidable intellectual opponents than...a Church that was shot through with a recent history of internal divisions (Protestant Reformation, religious wars) and corruption (selling of indulgences, corrupt popes, etc.).
That is because they do not currently see dysgenic decline as a problem. If it ain’t broke, don’t fix it. But if they ever became convinced that it was a serious problem...that the only people who were willing to voluntarily restrain their reproduction were the smart ones, and the Earth was getting re-populated only by the less-smart ones on average, to the extent that it threatened the very maintenance of civilization...yes, if somehow you could convince progressives of this (imagine if perhaps the world had indeed turned into a carbon-copy of the world in the movie “Idiocracy” and no progressives could deny it any more...well, what would progressives do? Agree to the social darwinism that the neoreactionaries offer? No way. Plug their fingers in their ears and pretend the problem didn’t exist? Not if the problem were self-evidently bad enough. Depend on voluntary initiatives? Then you are right back to the problem. The only way I could see of seriously addressing the problem while remaining true to progressivist principles would be a global eugenics program overseen by a democratic world government. This is the logical endpoint of progressivist principles when applied to this problem. And you know...me personally, I would be fine with such a eugenics program.