> It's also worth pointing out that there's been some evidence suggesting that, in the weeks and months leading up to the Russian invasion of the Ukraine, the "fill level" of the Russian-owned storage infrastructure within Germany was decreased, which would both be a way for Russia to attempt to leverage gas delivery against sanctions (in other words, blackmail), as well as yet another strong indication that the invasion was a deliberate Russian aggression planned well in advance.
It's a bit more complex than that. Following the liberalization of the gas market, "discount providers" appeared who simply bought on the spot market because that is usually drastically cheaper than long-term contracts, and also the large utilities shifted parts of their purchase to spot market contracts for the same reason. For many years this worked just fine from an outside POV, and the margins on the retail gas price that the utilities made were usually large enough to account for short-term supply price hikes without having to raise new capital or retail prices. All seemed to be well.
Last year, people noticed that Gazprom's storage facilities were unusually low. Gazprom of course denied any wrongdoing, they claimed they are fulfilling their contractual obligations and that's it. Which is objectively true and as a result, no regulatory agency had any legal authority to step in.
And now, with the invasion ongoing (and for a few months prior), Gazprom still kept their long-term contracts but unlike all the prior times did not supply much on the spot market - which led to the well observed price hikes and utilities going bankrupt or out of business because their "old" strategy of simply buying on the spot market didn't work out.
The responsibility for the current situation rests to a large part on the utilities who forewent resilience (in form of more expensive long running contracts) in favor of short term profits. We dug our own and the Ukrainian's graves at the same time.