I agree with Nakagawa. Too much cost and time. Websites would have to keep certificates up to date. Also, think about how much internet traffic is of no real monetary value to anyone. There isn’t much useful data to be gained from someone snooping on your cat video viewing habits. For some sites, it makes sense to encrypt traffic (banking, web-based email, etc.), but for others it’s just not necessary. You can use a browser extension like HTTPS Everywhere on Chrome to force encrypted traffic to some websites, btw.