until just a few years ago many small sites were not https capable because globally trusted SSL/TLS certifcates were expensive and difficult to get. the amazing people at LetsEncrypt worked hard to fix this, however many ancient sites have not been updated to take advantage of easy https access.

the danger of visiting a http-only site is real (man-in-the-middle content injection and private information compromise), but likely not much more than actualy visiting the site wth https. an http-only site is possibly indicative of an unmaintained server and therefore a server that could be previously compromised and serving malicious content. of course, the same applies to an https server, but my guard is always up on an http only connection. obviously I would not pass sensitive information across an http-only connection.

use precautions (e.g. javascript off) when hitting random servers if you do decide to click links.