Websites that collect personal or payment info use Secure Sockets Layer, also called HTTPS and TLS, to prevent data being intercepted. Other sites unnecessarily use it to hide 'not secure' warnings and improve rankings in browsers and search engines sponsored by SSL certificate companies.
SSL is one of the most common types of planned obsolescence. When a device's certificates expire, it can't access SSL pages, which doesn't improve security in any way. SSL also slows down sites. Some search engines like Wiby allow users to exclude SSL pages.
The Chinese government, the Internet Archive, Katy Perry, Nginx (server software used by Netflix, Dropbox and more) and the University of Washington don't use SSL.