4 division titles in a row, higher wins per season trend, all done with a high degree of self-developed talent. Of course it’s stupid to just assume the future will be exactly the same but the Brewers system is intentional, sustainable, and highly successful. What I’m more skeptical about is this idea that they cannot succeed in the postseason, just because they haven’t in past years.
Cubs defeatism is also stupid, and I suspect a high degree of it is an emotional rather than intellectual viewpoint. What you are saying is absolutely true, and further - we should expect the farm to start producing better talent.