I don't know about all of you, I don't like these new flat icons that everyone is using. What ever happened to the old icons, like on iPhone and Samsung they used to have them years ago. Those were good times. Now it is always these stupid boring cartoonish designed icons. Side note: Somebody please update this icon pack. I am trying to use it on xfce on arch but some of the icons aren't working properly because it hasn't been updated in a while. I'll donate to you right away if you do it. Link to the repo: https://github.com/madmaxms/iconpack-obsidian
My primary icon theme and widget style are 20+ years old and not flat in the least. You can still have that look and feel on a real computer if you want it (but you may have to compromise elsewhere or do some extra work). On phones, all bets are off.
Dunno what your issue with that icon pack is, but I'd bet there's a good chance it can be solved with a few file renames or symlinks if you care enough to bother.