I see 3 possible reasons:
The continued existence of a free and democratic Europe could remind US citizens of what they once had and how much better they could be living, which makes the continued existence and success (fingers crossed) of the EU an existential threat to US conservatives.
Or maybe Putin + Xi consider the battle for the spite and minds of US Americans won and so they're now moving the focus of their troll armies + proxies to the EU. If all trolls suddenly get the same new talking points, that's not organic, that's a strategic shift mandated from the top.
And the 3rd reason I can think of is the combination of the above, which I think is most likely. And if the authoritarians fail at making the eu fail, they'll double down on displaying the eu countries as dystopian hellholes to convince their own population that they have it so much better.
NATO is such a big threat to Russia, that as soon as Finland had joined NATO, Russia moved it's troops away from that area. Russia's problem with NATO is not that it sees a defensive alliance like NATO as a threat, the problem for them is that they can't bully and invade NATO countries should they feel like it. Which is also why all the formerly occupied countries that are next to Russia, want to join NATO. Who doesn't want their country to be safe from invasion by a fascist state? Tankies apparently.