In the past it made more sense to have a shitty webpage because open source projects don't tend to have graphic designers contributing to them, but anyone can AI a decent looking static site these days, so it wouldn't surprise me if some of those open source maintainers start choosing to use them.
Some people appreciate a nice looking site, they just didn’t have time to spend making it look nice. Now those people have the option of doing that without a huge time commitment, so undoubtedly some of them will.