he spends 6 or 7 pages on ultra-descriptive things about what somebody is wearing
I just reread the first chapter: no "ultra-descriptive things about what somebody is wearing" at all. And if you are writing realistic prose, what people are wearing is important, and in the nineteenth century even more than in the twenty-first; it's no coincidence that two key works of 19th century literature are Gottfried Keller's Kleider machen Leute and Nikolay Gogol's Шинель. Movies tend to get this wrong; I remember a relatively recent film version of Anna Karenina where one reviewer noticed that the clothes belonged to the wrong time (the 1890s rather than the 1860s) and the wrong social set.
Btw, the version of Бесы I cited above reproduces a printed version where the text of the novel runs to about 660 pages; another (old-spelling) version has about 580 pages. Either the translation is way too wordy, or the printer is wasting paper.
You remind me of André Gide rejecting Proust's Recherche.