I assume you are in a country with fire-at-will policies. In Germany you have a job security, you can't just fire people without a reason. The difficulty is actually proving their incompetence or unwillingness to work. Thus in my experience (working a self-employed contractor in Germany) this group is far larger than 50%. Also one of my reasons why no good software comes out of germany (and this includes SAP, as long as you show me a single end-user that is happy with working with SAP software).

The ability to deliver a 30 second summary in a daily standup has very little to do with real productivity.

Why is incapability to make progress at work tasks not a valid reason for job dismissal in Germany? Unless I am misunderstanding something

You have to prove it is the employees fault by intentionally not completing the task. Incompetence or incapability is not the employees fault, because well, you hired them and judged their ability - probably due to their education (it is a little more complex than that of course). As a concrete example, if you have a CS degree from the 80s and job as a COBOL programer and your employer decides to assign you to a new team doing react+js, the employee is still formally qualified. You couldn't fire him for incompetence, just because a 22 year old bootcamp graduate delivers 10x the results.

Yes I work in the US but my company has extreme time wasting practices designed to have engineers explain every thing they do and why it's worth it. I never found this helpful and find it causes more problems than it solves.

Incompetent workers migrating to the US is a big issue.