No, that's pretty accurate.
We're all fielding the same list because the units all play roughly the same with but are made obsolete by a different unit in this edition, with the only exception being Interceptors.
Want a shooty unit? Take Terminators because you can't shoot your psycannons on the move with any effectiveness with power armor any more..
Want a choppy unit? Take Terminators because you can't shoot your psycannons on the move with any effectiveness with power armor any more.
Purifiers and Paladins can't be troops any more, so we have to fill the troops slots and... oops, we're out of points!
Compare a Grand Master to a Chapter Master and you'll see why Librarian is the go-to choice. We're paying points for a psyker so we may as well take the effective one.
But besides my whining about the codex

...
I would imagine most 1000 point lists would be fairly boring to play with/against, because you're making huge sacrifices in what you're taking to fit into the points limit. Obviously a lot of cheaper armies can fit many different lists into 1000 points, but they can't fit a
good one without knowing what their opponent is fielding first. The reason why 1850 is so popular for tournaments is because it allows you to field a mostly
TAC list with most of the tricks and goodies your army allows, while still forcing some hard choices whether you want option A or option B.
With 850 points less, I imagine it's quite difficult to field a
TAC style list as opposed to a Rock, Paper, Scissors list.