Fantastic points!

"The majority of the teams had other issues. Many teams had the same stakeholders. And these stakeholders had too many reviews to attend. "

Yes: Agile 2 talks about this a lot. The root problem is recurring meetings. Meetings should be used for deep discussion - not sharing updates or other things that can be shared in messages, dashboards, or emails.

"We should have one Product Owner for that product as a whole".

Yes - Agile 2 also talks about this. We need to be product-focused, not team focused. Teams are important, but the product is more important. The leadership gap is usually at the product level. That is why Team Topologies has resonated so strongly.

Indeed, Spotify ditched Scrum pretty early on. It was in the way. A colleague of mine works at Spotify; they don't actually use the Spotify model - that was what some guy wrote about ten years ago. What best characterizes their environment is what they call "controlled chaos". It means that they don't have a process: rather, they have behavioral norms for how people are expected to react when they discover issues. The same is true at SpaceX.

Agility does not arise from process: agility arises from behavioral norms, supported by culture.