Do people actually like all of the overdesigned clutter to the point where it makes them not want to switch sites?
To me, the stripped down clarity on Lemmy is a feature. I remember back in the day when people flocked to Facebook from MySpace, in large part because they were sick of eye gouging customized pages and just wanted a simple, consistent interface. The content, not the buttons to click on it are the draw right?
https://github.com/soundjester/lemmy_monkey is what I use.
This assumes you have something like the firefox addon “Greasemonkey” installed. Anything that supports userscripts will work.
(edit – https://www.tampermonkey.net/ for Chrome/Edge, apparently. I just looked it up. If you need more help, just ask.)