The Kohl pyramid vs Eurofighter is a funny but very poor example that isn't remotely comparable. Useless defence projects have the advantage that it keeps institutional know-how from being lost and ready for the time when war actually comes for you. That's why Europe has been left unprepared by the war in Ukraine and why the US is the defense powerhouse.
Yup. It's one of those industries where an important part of the mission is reasonably level spending over extended periods. Much of the real cost is the cost of being able to produce it, this can end up being more than the actual cost to produce one item.
(Even more extreme: drug pricing. It can take a billion dollars to bring a drug to market, something has to pay for that. Unfortunately, the reality is that it's basically the US market that covers the world's drug R&D.)