Really... with Let's Encrypt and easy auto-renewals (and, in some cases, easy SSL certificate issuance!), there is absolutely NO reason to have a website that doesn't use HTTPS.

OK, I realize that's not true if your site is pre-existing. You still have to do the work to make HTTPS work properly without the browser complaining. But the major hurdles are GONE. Especially for brand-new websites, there's no excuse now.