That xyzDOTorg was just an example for 'some.website', but the forum-SW doesn't understand a joke - with or without url-tags, it turns anything link-like into a valid web-link.
Icon themes inconsistency ...
It's like in politics. If you want a solution any time soon, you need autocracy - democracy is anarchy and people discuss forever, but there's never any solution to the problem.
If anybody is allowed to write a piece of SW, make a 'design' etc. and dispose it into some Linux repository, without anybody ever controlling it or somebody inspecting it and sending the author to the gulag, because it produced such a 'messy junk-ware', what do you expect?
Have you ever checked the 'crime-folder' or the 'horror-folder' (/usr/share/applications) and inspect its contents? Very often, you'll find 'Icon=/usr/share/example/icons/example.png'-like cases with hard-coded paths in application starters.
Gnome is also often 'gnoming' with us and renames 'epiphany' into 'org.gnome-web.epiphany' ...
Both those things lead to having the icon, but not having it (because it doesn't get found).
There is no consistent icon set, and latest after you start installing any third-party SW, even the most consistent icon set will be/get ruined to some extent.
The most consistent icon sets ever were those from Mac OS X / macOS, but they also aren't/weren't perfect. If you closely examine Windows, it might look consistent at the first glance, but as soon as you dig into the depths, you'll find some yesteryear icons which seem to be out of place.
The most consistent icon set under Linux WAS Adwaita/Gnome/hicolor that you are using, BUT it also evolved. Please check Adwaita on Fedora 33. The problem? The name stayed the same - the icons not. Good luck with consistency if half of the icons are Adwaita (New) and the rest 'hicolor' (old).
Mate-Brave is basically Adwaita/Gnome/hicolor, with new Folders and a few reworked icons.
vs. https://ibb.co/YffgMVD https://ibb.co/kcZDMPL
Plasma icon set is kind of irrelevant - it is nice, but even on Plasma, all my important applications are still Gnome or 'independent' which look and behave on their own. Consistent inconsistency results.
The most consistent modern AND flexible icon set today is Papirus, but the problem is that just about every 'modern' distribution is using it. That makes it the best worst choice one can make.
Third problem is technological and would PNG/SVG icons and qt-4/5, gtk-2/3/4 ... aurora, murrine, pixbuff ...
The Antü icon set I used for on my screenshots is an KDE icon set and is missing most GTK icons. It kinda works solely due to 'cascading.
Every icon theme has a descriptor file with line like: Inherits=Adwaita,highcolor
The purpose of that line is to tell the system where to look for the icons, if the needed icon is missing.
Here you see two times same, but slightly different - because of cascading.
vs. https://ibb.co/SXNMRZH https://ibb.co/2KCgHtJ
For example, you'd like to use Paper icon set, but you're missing half of the needed icons.
First you install the Paper and the very similar style Papirus icon sets. Then you change the Paper's
Inherit-line to: Inherits=Papirus. For every missing Paper icon, Papirus icon will be shown (if it exists).
That's what I'm calling 'cascading' and it's best you can do about the consistency, unless if you decide to produce your very own icon set. That could take a couple of years for a whole team of artists.
This is Paper: https://ibb.co/yh3qfcm https://ibb.co/pwWkt7s
Paper side by side with ZorinBlue-Light (recolored Paper): https://ibb.co/8dVQb4j
Original Papirus (with Pink Folders): https://ibb.co/WyF1phw
https://ibb.co/Yy027LQ https://ibb.co/Qp0K9XZ https://ibb.co/4TZDMjN
Ignore missing icons - this is what I'll have to fix.
As of wallpapers:
https://ibb.co/zGydk7f https://ibb.co/sVG0GQC https://ibb.co/MSxFb0Q
is Apple https://ibb.co/BLGMnpy
is from MX-Linux 17 or 18 - No idea where do they have it from.
Maybe: http://wallpaperswide.com/minimalist_bl ... apers.html
(check the file name!) form MX-19.
came on Nokia Booklet 3G with Windows 7 Starter - probably Nokia.
is from Rosa Linux Gnome 8 or 9.
https://ibb.co/Kbk8nCf https://ibb.co/sgqgyX4 https://ibb.co/ZH9sM2Q
https://ibb.co/HgvhZz4 https://ibb.co/QP3x5gT https://ibb.co/RBmQ4Bc
are from: http://simpledesktops.com/
(Filtered: 'minimal' / 'flat')
Most if not all, are anyway, all over the different wallpaper websites.
https://www.wallpaperflare.com/search?w ... minimalist