I dunno man while the revival was not great I feel like the X-Files might be only second to Game of Thrones on my list of shows that did not end on high notes. It went about 3-4 seasons too long.
“Mulder and Scully Meet the Were-Monster” was funny though.
“Rm9sbG93ZXJz” almost precisely presaged the entire plot of all of the Black Mirror episodes combined, and was great fun (particularly the near-total lack of dialog). I thought the “My Struggle” bookends in Season 10 were quite good, but then Season 11 retconned the whole plot away.
Both of the Darin Morgan-penned episodes were good (The Lost Art of Forehead Sweat, despite some on-the-nose politics, excellently recontextualizes a show about about conspiracies in the age of social media; namely that "the truth" doesn't matter at all).
The characters weren't consistent with the previous seasons. No vulnerability from Scully and no cerebral aspects to Mulder; he doesn't really work as a pure action hero.
Unfortunately, I don't remember it ever ending on a high note before that though.