The reasons behind the creation of Scrum and the reasons behind the adoption of Scrum are different.

Plus, most implementations of Scrum are bullshit. Scrum does not recognize the role of a "project manager". There's the product owner, the scrum master and the development team. That's all.

The scrum master only exists to guarantee the process is followed. The scrum master is just a scrum evangelist, not a real leader.

And product owner and scrum master need to be highly skilled people with a lot of responsibility instead of whoever has nothing better to do at the moment as is so often the case.

I still can’t figure out how line managers and architects fit into a well run scrum environment. Seems they would be losing a lot of power.

Scrum does not formally recognize levels of seniority. All members of the development team have the same role.

You can read the official Scrum guide here, it's a few pages long:

https://www.scrumguides.org/docs/scrumguide/v2017/2017-Scrum...

I think Scrum exists only to expand the adoption of Scrum. That is at least the reason behind the role of "Scrum master".

By maximizing adoption, the authors can personally benefit and become rich and famous.