This story is good, but there's a couple of caveats, I think, before we proclaim that drones were definitively the answer of what went wrong for Armenia in the war here. https://twitter.com/John_Hudson/status/1326638714915876869
The simplest explanation, from the Washington Post story, is the least flashy one: Azerbaijan actively prepared for the war, and it had the formal backing and possibly direct help of the largest other military to get involved in the war. That alone is likely a sufficient.
Open-source intel does important work, & I mean this as no critique of the analysis below. But creating tallies of losses from publicly uploaded video of airstrikes is the wartime equivalent of a drunk looking for his keys near the streetlight: it's availability bias.
That's true always when it comes to open source, but it is especially true when the specific weapons in use are equal parts missile launcher and camera. The propaganda role of drones is huge! I found @RikeFranke worth reading on this: https://twitter.com/RikeFranke/status/1313462717609541633
Here's what I wrote about the drone aspect of the war last month: "In all the focus on drones as a weapon, it is so easy to lose sight that, for nations looking to claim victories, an abundance of drone shot video is an ends unto itself." https://athertonkd.substack.com/p/kettering-bugsnax
I like this early analysis found in @WarOnTheRocks: "A social media feed composed largely of drone video footage could lead one to believe in the dominance of such systems, even in a conflict where many casualties are still inflicted by armor..." etc. https://warontherocks.com/2020/10/the-second-nagorno-karabakh-war-two-weeks-in/
What is perhaps easier to establish than the special effectiveness of drones is the ineffectiveness of existing anti-air weapons against them. We saw this in the Russian experience failing to counter small drones in Syria, and it's no less true here.
(An inability to deal with small drones has motivated a lot of Russia's military tech development, as @SamBendett has said many times: https://www.forbes.com/sites/kelseyatherton/2020/07/23/russia-prepares-robot-tank-for-fighting-drones/?sh=63a711e85fb5)
The availability of drones in wars like this makes it hard to know, exactly, if old anti-air weapons are ineffective generally, or ineffective especially against drones. Because there's no risk to a pilot, & because the airframes are cheaper, it's an easier risk for a military.
Counter-drone technology, as a whole family of devices, has yet to offer anything as comprehensive or immediately ready to counter drones as anti-air missiles provided to jets in an earlier era, or as flak cannons provided against prop-driven bombers before that.
If I had to make a prediction (and why not, this is twitter), the technology lesson from this war isn't that drones render armor irrelevant, it's that armor will need mobile anti-air cover that can hit drones effectively and on a moment's notice. A second coming of flak, maybe.
The other lesson of drones in wars between countries is that having a sky full of armed robots filming propaganda the entire time is a possible way to shorten the conflict, by creating the impression that they are decisive, even if the facts on the ground suggest smaller impact.