I stopped reading right here. Let's add some context around this, shall we?
First up, the game isn't declining in popularity. That's just a white lie based on bad data. Madden NFL 19 was the fourth-best selling game in the United States in 2018 per NPD. Second, we are all well-aware that reported sales figures of video games haven't included digital copies for years. NPD has ways of tracking those, but those numbers are held privately. We further know that digital sales now account for about half of console video game purchases.
To add further context to any apparent drop in release-date sales figures, Madden NFL 19 (and M20) released well before the NFL regular season started, unlike Madden NFL 13 (and basically every Madden up through M18 inclusive) which released at the end of August when hype for the NFL season was at a more fever pitch. Even if we take the declining launch window sales at face value, given that we know Madden still sold like hot pancakes based on NPD's reporting, it is reasonable to argue that Madden's launch window is not as important to its sales as it is to other video games and thus not indicative of the game's popularity.
From this alone, it's my opinion that this writer is clearly cherry-picking facts to support a conclusion he reached well before he put the game in the console. He wants to paint a picture that the game is declining in popularity and quality based on misleading facts and his own apparent bitterness. To be fair, that's his right - a review is an opinion piece - but I similarly have the right to criticize his opinion and dismiss his words in turn. I don't care to read anything past that first couple lines.
Side-note: what is it with specifically the Madden community and the cheerleading of negative reviews which dunk on the game? Like, why should that make any of us happen?