For what it is worth the data is based mostly on Google Trends both as a YouTube search or a Web search for the game. I also have played the game since 2016 and am active in several communities as well as have been a creator for the same amount of time. All creators I know and play on SMPs with in the space report drops in the viewership of their MC Content...particularly over the past 1.5 years. They have tried variations to the content and nothing sticks like it used to.
Player counts from various websites I have found all vary too wildly to really use as a source and actually isn't all that indicative of what a community is feeling overall toward a game until the bottom actually falls out. The popularity of the game is much better seen by people who are actively searching for it or to learn something about a new feature as in YouTube or Google searches as that shows "fresh" interest vs showing how many die hards a game has. Take Halo MCC as an example. Still a lot of people play and swear by Halo 2 but the game is in fact long dead.
In the various communities I interact with the overwhelming majority of players are getting more and more upset with Mojang over the points we brought up in the video itself...that was the basis for a lot of those points. From what people are talking about in the community. Their anger over chat reporting info, the firefly fiasco, Birch Forest disaster and the terrible roll out of the Deep Dark over basically 3 updates that was supposed to be one major update.
Sometimes in communities passion can overtake what the real "vibe" is but in these cases...the criticisms of Mojang are mostly legit and not over the top so it is much easier to see that a large number of people are really fed up with the direction being taken and it is resulting in less and less people finding any reason to come back to the game once disappointed enough to leave it.
