I've noticed that new wiki design needs a bit of fixing, mostly in
accessibility department (it's not easy to read).

Let's start with basics:

a) It's monolithic - there is no distinction between page elements which forces
user to specifically look for what they need in a wall of text instead of
finding what they need or may need through natural flow of the page browsing. 

This happens mostly due two issues:

* lack of distinguishable features that differentiate parts of the page
(usually done with background shades/colors and/or elements borders)
* font formating is all over the place (from font size to weight)

b) Golden ratio, a foundation of ANY, ANY quality design from ancient greek art
to modern photography to system UX to web... is nowhere to be seen on wiki
making everything completely disconnected, random and not pleasant for the user
(for example, it's very easy to spot on badly formatted books or newspapers
when you suddenly get taken out of the content and notice that something is
wrong with text, but don't know what exactly)

A bit more about golden ratio here: 
https://apiumhub.com/tech-blog-barcelona/golden-ratio-in-web-design

Even openSUSE own artwork guidelines seem to agree:
https://en.opensuse.org/openSUSE:Artwork_guidelines

I know that someone put work into new wiki design, but openSUSE deserves a bit
more. Web presence is big part of marketing and even a foss project is always a
product and should be treated as such, otherwise it will fail.