Truth to be told, after reading two paragraphs, I was about to type in a comment something along the lines of, take ownership and do things incrementally. And as I read a bit more, I knew that u were on to something!

IMO, the real conflict is about ownership.

If you think of PM's as owners, then they will stack you with features and cute little experiments.

If you think of PJMs or TPMs as owners, then you will be harassed with deadlines and optimizing to the brim work.

If the engineering team ownership is left to the TL+SDM combo, then we can focus on ensuring systems stay healthy and be impactful at the same time because there is a healthy push and pull between eng and product.

IMO, any time we have agile coaches and project managers start running the show, thats a sad engineering culture. I'm not saying they are not useful, but if they are determining the 100% of all work done, then its a bad engineering culture, imo,