Also changing tastes in clothing have reduced the gap between luxury clothing and cheap clothing by a lot, while home improvement needs remain more or less steady.
The point of NM et al. was that they currated what you could not obtain yourself (outside of a private buyer's agent and/or flight to NYC).
With the internet... suddenly manufacturers could efficiently sell direct to consumer. Or at worse, via something like Huckberry that has far lower overhead.
The value proposition of brick and mortar curration evaporated, and the only thing that kept them going was generational intertia and loyalty. And the problem with an aging customer base is eventually they age... terminally.
Financial games and leverage may have exacerbated things, but you can only shrink for so long.