I read it briefly, I did not see any information about what version of Scribus you used?
I evaluated Pop!_OS, whose app store currently has Scribus v1.4.8. When I mention exploring the 1.5 series, that was on Mac OSX, where I was using Scribus 1.5.4, which I downloaded from the Scribus website.
Since you mention reading briefly, I recommend you read the third and final post to the end. I doubt you will dislike or disagree with my conclusion.
...comparing a fairly "young" Scribus with a "mature" InDesign is not really fair.
I would tend to disagree. It is fair to the extent that I am performing an evaluation of whether or not I can achieve my particular goals with one piece of software or another. That is merely a technical evaluation of two pieces of software. Technical evaluations happen quite frequently, both in professional and personal computing contexts. I did not set out to make any sweeping claims of "rightness" or "validity" of either piece of software. I merely wanted to find out if I could discover a Scribus workflow capable of replacing my known InDesign workflow.