Very true.

But it does say that you can't change it - and yet they are always changing it.

And by defining certain practices, such as the retro, they imply that that is when you bring up issues - thereby discouraging people from bringing up issues as they occur. As another example, the sprint review is when you show the PO things, so it is natural to reserve all demos for that event.

Perhaps the biggest problem with Scrum is that is encourages people to focus on the wrong things. They obsess over whether their standup is correct, or their retro is correct, or if their stories are correct. But all those things are not what really matters. What matters is whether issues are being identified, and discussed, and good decisions are being made. What matters is if the product quality is being examined, and the test coverage is being assessed against the product quality. What matters is how fast people can get new features out. What matters is whether the product is the right product. What matters is does the organization understand the data that the product is pushing into the data lake, so that the data can be used for BI and ML. Those things all matter, but Scrum misses all of those.

And the cadence forces people to interrupt their work, and participate in activities they don't usually want to participate in: forcing collaboration into regimented ceremonies that are burdensome. Truly agile organizations don't use ceremonies like that: https://vimeo.com/709926801