"Connection to site is not secure" on http. What is the problem?

Question

Digital certificates

Played around with SSL, but later turned it off. But browsers even at http swear on safety.

The site www.magazin-system.ru I checked

the search on the page, there are no internal links with https.

Answer 1

So everything is correct, http is not protected

Answer 2

But browsers even at http swear on safety.

Not browsers, but a browser from Google. And this is not security, but a divorce. https - encrypted protocol. not "protected", "secure" or "superduperslohavmecha".