first off, let me say, for me. I use Caddy (https://caddyserver.com/) and it just works. You start it, it gets a cert from letsencrypt and starts serving https. So it was (almost) zero work to serve with https.

As for reasons to encrypt

1. Prevents (I think) ISPs in the middle from injecting ads, spyware, phishing scams, etc on top of your site.

2. Prevents 3rd parties from seeing what pages the user is accessing. Some people would prefer that other's can not read over their shoulder and see what they're reading.

I know for me, I'm sensitive to that particular issue to the point that I don't really want to use Netflix, Amazon Prime, Spotify, etc. I really don't like the idea that they're building a profile of me based on what I watch and thinking they know who I am based on that.

It could be as simple as I don't want it known if I'm reading liberal or conservative blogs.

I'm sure others might have other reasons they don't want a 3rd party to know what specific pages they're reading.

---

ps: I get there are other ways to track me but I'm fairly confident that I'm avoiding most of them via HTTPS, VPNs, Private browser windows, multiple profiles, 3rd party cookies off, ad blockers, etc....