Examples could be things like specific configuration defaults or general decision-making in leadership.
What would you change?
If you don’t want ANYTHING installed by default you should probably just go for the specialized distros that provide that.
The issue with many of those distros is that it usually means that you have to install everything from 0.
Arch is good at this because the archinstall script speeds it up and you don’t have to choose a DE. But with other distros that use a graphical installer, you are forced to use whatever they ship as the default desktop environment.
edit: And holy shit properly configuring Btrfs subvolumes from 0 is something that I tried with voidlinux and I ended up breaking the entire install.