All of this being said this puts a lot of pressure on product managers because it’s hard for them to express how long something will take. The key here is that even if you do all the ceremonies you don’t really know how long it’ll take anyway.
The only way you can work like this is if you have built up trust from your PM. If you can throw all of the shit away and give the PM what they want they’ll go to bat for you. For agile to work there has to be an incredible amount of trust that every team member is going to do what they say. And the lack of trust is when you get Agile™