I've been Agile exposed in so many different ways I can barely remember what the hell Agile really is supposed to be anymore. The worst thing that can happen to developers is "We're running or own take on Agile", because "our own take" means "negatively effective".
I've got colleagues who have been required to go to 10-14 hours of ceremonies each week because they don't need a scrum master and PMs murder them with meetings where they demand to be heard for hours for no reason other than the PMs have nothing better to do with their time. Hell, I have colleagues in that situation right now where I work.
I know of other teams that (and this continues to be a complete disaster) that have an open door policy on requirements. Work gets tabled all the time because the manager wants the internal customers to feel super special and any new requirement that comes along can out-prioritize something that is 99% complete. Makes the manager appear great (somehow) but the devs look like idiots because they never finish anything. Thankfully everyone I knew in this company has vacated...
My boss had been running a relatively successful Kanban but was forced to move to Agile Scrum recently due to some guy's decision up the ladder. As a team we've made the transition relatively effortlessly in the mind space. I mean, before I'd assign work to my team based on requirements that may not fit into sprints, and it worked very well, since I knew their skills very well. I could time manage the whole thing without a lot of thought and everyone was busting out good work left and right. The only difference now is I have to fit all that into sprints, which makes things harder. I'm not supposed to give out anything that would split an iteration, and therefore I either have to spent a lot of time cleverly breaking up projects so that work can continue, or give out 1-2 day assignments just to take up my developers' time.
As I'm the senior/lead/architect of the project this is definitely the wrong way to do things. All the above reduces MY time to develop from about 36 hours a week to 25-28 because I have to play scrumbag, as well as all the other rolls, and we've been saddled by a tools that doesn't' work so well. But I do a damned good job insulating my team from PMs and other managers (ours is really good at wasting time, too, but at least understands Agile).