You're failing to take Paradox's lifecycles into account. Even though they're only the publisher, keep in mind that they're used to supporting games for 8-10 years after launch. Cities: Skylines came out in 2015 and has seen continual development ever since. Its performance was also abysmal at a point, but people kept playing and the devs kept improving it to the point where nobody even fully remembers why we cared about SimCity going to shit when Cities: Skylines was right there.

problem is not on a development level, but rather on a project management and (particularly) an executive level.

In any industry as time progresses the production becomes more and more capital intensive and that needs more and bigger investors and all that capital means that there is a bigger risk and that is mitigated by the investors by requiring "their guys" to staff the management and these people are unusually really bad for the technical and actual value side of the business on the long run, because they are usually people with financial or marketing backgrounds. They fundamentally work by the logic of profit maximization and there are always easier and more surefire ways toi achieve that than with supplying a good product. It's even worse when the end product is something that could be considered "art". In AAA it all eventually leads into pushing bland installments under rushed deadlines for the same once successful franchise out one after another, just because that is where the risks are lowest and money is still being made.