To be fair, most of time you can just Google %appname% screenshot. I understand that this is not as convenient as having screenshots in the readme, but eh, it’s not as big of a problem when you realize this.
P.S. I do actually add at least one screenshot for my software. Maybe because sometimes UI is one of the main focus, idk. I just feel like it.
Well that’s what FOSS is. You can always contribute and add screenshots if you’d like.