I'm a typographer and sometime book designer (as well as a programmer). I've also used InDesign since 1.0, so I'm very familiar with what it does. Having said that, I'd love to find an alternative -- InDesign has gotten bloated and awful over the years, not to mention the dreadful subscription policy. (It's one of the few CC apps for which I
cannot buy a standalone/perpetual license.)
However, Scribus comes nowhere close to InDesign. Here are several basic things I require from a page-layout application if it's going to be any kind of competitor to InDesign:
1. Work in picas and ems, not inches. (Inches are fine for specifying page sizes, but beyond that, picas are the standard in typography.)
2. Be able to zoom arbitrarily. Scribus doesn't seem to support zoom levels more than 400%, so I can't work with even medium-sized text at all accurately.
3. Be able to easily set kerning and tracking on arbitrary text. The Scribus manual caims this is possible, but mucking around with the latest dev version (1.5.3), I couldn't figure out how to do it. (I did really well at totally fucking up my layout just by scrolling, through. Scribus is a bit too response in some ways.)
4. Be able to use OpenType features. Apparently Scribus 1.5.4 will include some of that. But to a typographer in this century, OpenType is essential, not optional.
Apologies to the Scribus developers, but being told that it's a capable publishing app is a bit like a C programmer being told that BASIC should be just fine for them -- hey, they're both programming languages, right?
And yes, I've attempted to use TeX (and LaTeX, and ConTeXT, and XeLaTeX, and...) to do high-quality typographical work. It's possible, but the amount of effort to undo Knuth's poor aesthetic choices (not to mention interface with archaic architecture) is significant, and frankly, not worth my time.
Grumpy typographer is grumpy.