The usage of HTTPS has been steadily increasing over the past couple years, but it is still not everywhere. For example, many news sites still do not employ HTTPS by default. One of the most notable sites that still runs on HTTP is eBay. This may not seem like a big deal at first, but there are consequences for not using this basic security measure.
Users that access HTTP sites are susceptible to man in the middle attacks. This type of attack allows a hacker to modify a web page and if they are on the same network, it is very easy to steal log-in credentials or even credit card information.
At this point, you may be blaming large websites for not switching to TLS, but users are also to blame. Older versions of Android continue to have difficulty loading encrypted pages. As time goes on, those users will slowly upgrade their outdated handsets so they can finally meet basic security standards. There is still a significant amount of work to be done, but we are getting ever closer to reaching 100% of sites on TLS.