Comment by overshard

If you're not using HTTPS it is trivial for anyone in the middle of the "client to server and back" connection to change any of the content.

If you use HTTPS you prevent alterations to that traffic and people receive exactly what you expect they should receive.

Examples of recent ISP misbehaving on non-https websites just 25 days ago on HN: https://news.ycombinator.com/item?id=8500131

Note that the Verizon issue isn't anything entirely content altering but someone who lives in a country with strict monitoring of traffic could easily change the wording of your website to match their propaganda if you aren't using HTTPS.

So yes, your content is publicly available free stuff and no one is probably sending you user login credentials or credit cards but it still matters.