It's known as the Dark Ages for a reason. Society regressed in most ways. Maybe because of the collapse of the Roman Empire? Europe only started finding their feet
during the Reneissance.
https://old.reddit.com/r/AskHistorians/comments/235w3l/why_a...
The European Dark Ages narrative was indeed overblown and needed correction. But this correction went too far. It seems to be now at the stage of explicit and vigorous denial of any downfall of fortune in the Western ex-Roman provinces. I'd posit that such a denial is even more overblown than the initial myth it aimed to correct.
I can offer you a link to an author arguing for this position: https://slatestarcodex.com/2017/10/15/were-there-dark-ages/
Regardless, your link is an interesting argument that doesn't provide anything especially compelling to the contrary .. a void, here a void in the record, is easily filled with speculation.
Please read some unbiased history books.
Catholics: Copernicus, Mendel, Pascal, Ampere, Fermat, ... And The Renaissance is always skipped by them for some reason.
Figures like Napoleon or The Catholic Monarchs were cowards and stupid?
But I think I'm wasting my time answering you. You seem quite closed minded, blue team, read team.
As to your last point, i view myself largely as an unaffected observer, who likes to poke holes in certain liberal narratives.