The article was obviously about the big picture.
You get that only when you look at a bunch of "unrelated", "small" facts. If there are a lot of facts pointing in one direction, maybe there is something to it.
The other point is: That was not cheery picking. There are no other facts that would point in the opposite direction… More or less everything in Germany is in decline. That's just true. Source: I'm living here since about 40 years.
Though the article interpreted something quite wrong in the very beginning: The decline started quite exactly around 20 years ago. It was caused by the move to ultra-capitalism (the mentioned big social reforms 20 years ago), which made Germany a low wage country, which made the people poor and started an exodus of the well educated parts of society. The reforms made some of the numbers capitalists are interested in look good for some time, but at the expense of maximally "squeezing out" society. Now this short sighted tactic backfires.
By now almost 1/6 of the people here are poor (and 1/4 is at risk of becoming poor):
https://www.malteser.de/armut-in-deutschland.html
Almost nobody can afford children. ("Bio-Germans" are foreseeable dying out therefore, and it doesn't look like this is avoidable any more when you try to play the numbers game. The article showed the relevant statistic. At least we get some migrants; with children. But the "Bio-Germans" hate migrants. Also this may pay off not before one generation; we need to educate the children; but the education system is broken…)
Actually it's getting hard to even afford a living place. Liberal housing markets made space in areas of high population density so expensive "normal" people can't afford it any more. At the same time building new housing is too expensive and nobody invest in that. Which made companies in the building business die out, and even if the state would massively invest in housing right now we don't have the capacity to build that stuff. And even if we would have the firms, they would not find employees…
https://www.mieterbund.de/fileadmin/public/Studien/Studie_-_...
(Fun fact: AFAIK if Germany would build enough housing it would completely miss it's green goals, as building housing creates a lot of CO₂.)
The complete dependence on the car industry becomes a real problem at the same time. It's not only the big car manufacturers. But the largest part of "the Mittelstand" are external suppliers for the car industry… Should this implode (and it looks like that, as China is flooding the car markets, that's a fact) this will have catastrophic results for Germany. We simply don't have anything besides the car stuff. All we've got is already gone. And what's left is leaving because of he astronomical energy prices.
Big players are moving elsewhere, the smaller ones just die. Result: More people becoming poor, which just accelerates the downward spiral.
In regard to modern tech, like IT, Germany is a developing country. We're completely depended on the US and Asia in this area! People are making jokes about "Russian computers"[1] but the sad truth is we couldn't even build such a thing on our own.
In the last decades the education became completely messed up also. They tried to make everybody go to university; which destroyed the previously high class educational system. By now even the firms offering apprenticeship in handicraft trades complain that you can't find people skilled for that as the people coming from school can't properly read, write, or do basic calculus. (Source: I've talked to people offering apprenticeships, not only once, and I've had some contact to the youth.)
At the same time politics try to just close their eyes to most problems: If you listen to the local propaganda "everything is good" or, currently, "It's Putin's fault!". (That's not completely true, of course, there is some critical thinking even in mainstream here and there, but they hide it usually under a really large pile of straight propaganda; and it became quite seldom. This wasn't always like that. Even the state media was much more critical 20 years ago. By now it's obviously just coordinated propaganda. We actually pay over 10 billion Euro for our state propaganda…)
The article was actually refreshing unpolitical. You usually don't see such "pure" recitation of facts in the local (and especially state) media. (I was waiting the whole time while reading when we "get to the meat" and I get informed what we should buy to safe our souls, or who to blame for all the problems, but to my surprise this part never surfaced. The article looked almost like proper journalism from decades ago).
Just naming those facts is actually considered "right wing activism" here in Germany. You will get canceled quite instantly for saying the things the article said if you state such stuff for example as comment in some of the mainstream media outlets. Yes, they cancel for reciting facts. Especially if the recited facts have potential to "irritate people", and you present some proper numbers to make your point.
(Disclaimer: I'm not supporting any political party any more. I was once "leaning to the left". But the lefties are by now the same scammers as every other political movement. All these people in politics just care about redirecting state money into their own pockets. No difference the "color" or "side" of the political movement. Kleptocracy in it's final stage. Peak capitalism. This won't end good… And if there wouldn't be the language barrier I would actually start to consider to move to China. It's getting noticeably worse here and while looking at the current state of affairs it foreseeably won't get better during my lifetime anymore.)
[1] https://www.heise.de/news/MIG-Akinak-Russlands-selbstentworf... (See also the comments!)