This is weighted by site, and counts cnn.com and jefftk.com equally. My understanding is Cloudflare is dramatically disproportionately popular among small sites, I think because of how generous their free plan is? If they were 76% of traffic I'd be worried, but I think a majority of the sites using CF probably are signed up because "why not?", which doesn't actually give CF that much power.
It does count them equally and I agree it's popularity is mostly because of the free tier. From the same website, there is a graph and Cloudflare is lower for high-traffic websites than Cloudfront, Akamai and Fastly. [0] But regardless, that gives Cloudflare power over a lot of sites.