As per usual, it depends. The main problem with YouTube channels like these is that they don't state their sources/references, either onscreen or in the video descriptions. Onscreen would be ideal (which would be the equivalent of a footnote at the end of a sentence in a book), but even in the video description (equivalent to a bibliography/further reading section) would be nicer than what most YouTubers do, which is nothing. That keeps YouTube videos harder to account for mistakes, and makes it harder for interested readers to further their own studies beyond the videos.

Let's take one random example I've been recently thinking about, the Estonian YouTuber Eastory. They make videos usually focussed on military history, and often on World War II, so it's a topic I'm fairly well-experienced with. Here is a video they have done on the German Wehrmacht's Western Campaign against France in 1940.

Let's take a random section, say, 0:11 seconds in (just as the timer switches from 0:10 to 0:11). The military situation depicted seems generally accurate from my knowledge about the Western Campaign. You have the 10th, 1st, and 2nd Panzer Divisions in the southern German sector (that's XIX Army Corps on its way northwest to the channel), further north you have the divisions of XXXXI Army Corps, and further east you have the ever-frustrated German infantry divisions attempting to keep up.

So, the good news seems to be: there is significant and genuine work behind the map's creation process. But here is where you might run into issues. If I look to, say, occupied Luxembourg, I see two random infantry divisions, 44th in the north and 82nd in central west. Even with my comparably strong knowledge of German military campaigns in World War II, I do not know by heart if these two specific infantry divisions were in these two specific locations at this specific point of time and I do not know for certain that no other units were in those sectors either.

Where do I have to look to check that they were actually in these approximate locations in occupied Luxembourg on 17 May 1940? Do I look at the OKW or OKH war diaries? Do I look for a war diary of an army group, a field army, a corps, a division (the latter will be difficult since almost all war diaries of German divisions of World War II have been lost due to a fire in the archives in 1945)? Maybe there's a great piece of secondary literature that provides a day-by-day overview of the campaign, with daily maps, that Eastory used to make this animated map, or at least division-by-division histories? The latter I actually know to exist, but is it Mitcham's? Tessin's? Maybe I need to look up a postwar publication by a veterans' association of the 44th Infantry Division? Maybe a national history of Luxembourg? Maybe Allied intelligence reports? Maybe intelligence reports by Germany's axis partners or by neutral countries? Who knows?! I don't. I'll give Eastory the benefit of the doubt, because the factoids of the videos that I do know by heart all seem to be solid, but "benefit of the doubt" is a lot weaker than "properly cited bibliography".

So that's the crux of the issue. YouTube videos as a medium don't seem to instinctively lend themselves to historically accountable scientifically solid writing. Some videos (like Eastory's, who I specifically picked as they seem to be quite thorough in their research, even if they don't properly state it) are certainly less egregious than others, but YouTube videos about history are not created for historians or even laymen with genuine interest in historical authenticity.

And it's not just YouTube either. It's worth remembering: the reason that the History Channel got infamous for its Ancient Aliens program is because there is a significant overlap between "people who are interested in history" and "morons". There's a lot of money to be made by catering specifically to the latter demographic.

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And of the specific examples you cite, especially Armchair Historian and Extra Credits, there have been numerous people here on Reddit not that happy with their works' historical authenticity. I'm sure /r/badhistory has plenty of materiel for you to read further into in that respect.