Using webp and dithering?

Making images lighter with webp is an easy conversion. That's what this website actually uses. LowTechMagzine has talked about using dithering to make images more light weight, Decker, K "By dithering, we can make images ten times less resource-intensive," it apparently doesn't need to be done. It's because another site from SimpleThread, has gotten bigger file sizes. I'm not sure what method of conversion to get such low image size for low tech magzine was, but I wonder, what if I used dithering then converted to webp. Maybe that would make the image even smaller?

https://solar.lowtechmagazine.com/about.html

https://www.simplethread.com/why-your-website-should-not-use-dithered-images/