You get to decide, really. Screenfetch still works, but neofetch is pretty much the clear winner. People seem to have forgotten about the venerable screenfetch, so it's really more about reminding the world that it still exists and still works just fine.
The differences I can see between the two is that the display icon of the distribution used is that:
1. screenfetch shows it in partial lighter colors than neofetch.
2. screenfetcch shows disk usage and neofetch doesn't.
3. screenfetch shows Font type and neofetch doesn't.
4. Some minor difference of screenfetch showing the CPU temp
6. screenfetch doesn't shows the color palette you use and neofetch does.
In short mostly the same, but I still prefer using neofetch.
Pretty much. Neofetch is pretty much superior in every way. But, screenfetch still works and I kinda wanted to remind people that it exists. Heck, newer Linux users may not even know it exists.