Engineering had some firings in 2017, and we were supposedly left with the best ones.
Problem is, things took a 180 curve somewhere, and it became rough in 2018. Maybe management is to blame, but we changed that too and it kept getting worse.
The people that were fired had some really bad performance, and the team itself agreed on the metrics beforehand. Also, it took about a year after they were fired for the problems (other than their slowness) to start.
Read the books by Rands to understand the difference. And his blog posts about engineer personalities and group dynamics.
I've seen this happen, and many people just didn't like where things were going, and how (the "how" was particularly influential, needless to say).
Oh, we're also in our fourth product manager in three years. The previous three left because they were (of course) unable to deliver.
I’d probably only be concerned if they were delivering the wrong things (e.g. if business requirement <-> feature translation goes wrong).
Yeah, that's something I also don't understand.
Honestly, I'm a bit inclined to think there is a problem with engineering, since they were able to test lots of different strategies and group dynamics in the last three years, and none of them has worked so far.