Chrome 79: https sites don't load while http works fine
The bug, which apparently affected 10.10 (Yosemite) and 10.11 (El Capitan) only, has been fixed in Google Chrome 79.0.3945.88.

The changelog doesn't mention it though.

So download the latest installer, install it, remove any method to block Google updates¹ and be happy again with a working Google Chrome browser.



¹: I disabled access of ksfetch/Google Updater to gvt1.com and google.com with a packet filter