There used to be an extension for Firefox called "Open in reader mode" that adds an item to the context menu for links to... well, open them in reader mode. It'

There used to be an extension for Firefox called "Open in reader mode" that adds an item to the context menu for links to... well, open them in reader mode. It's not quite what you want, but I found it to be very helpful. I haven't used it in a couple of years, though, so I do not know if it is still around/maintained.