However, we've noticed that each team focuses on finding a local maximum, which creates a global complexity or "debt" that can negatively impact the company's global metrics. No single team is accountable for these metrics, and it can also hurt the local metrics of past efforts and future velocity of many teams.
I'm reaching out to ask for ideas and experiences with addressing this specific problem. Are there any frameworks, processes, or ideas that you have found helpful in balancing local maximums with global metrics in cross-functional teams?
No single team is accountable for these metrics
That's the core of the problem: if a maintainable / observable / whatever-able system is a desired goal, some team needs to own it (especially in the organizational structure you've described).There are likely already people doing this work in your organization, they're just having to juggle it along with their "on-topic" responsibilities. Find those folks and figure out how to either let them get back to their main job, or make the global concerns their main job.