I once worked at a place full of Agile cultists, including a bunch of "certified" "coaches." They spent about 1/4th of the time in planning meetings, retros, grooming sessions, sending emails about updating percentage complete on jira tickets, etc.

They made some of the dumbest technical decisions I have ever seen, were perpetually rewriting things, changing core APIs, breaking other parts of the system. The stuff barely worked, and this was after 5 years and dozens and dozens of developers.

The place was so dysfunctional, you could not even create your own branch in source control. You had to request it from the IT group that maintained the "enterprise" SCM server. The IT groups were doing their own form of Agile, so these requests could take weeks.

Truly awful.