The exceptions may be, as you said, online tutorials etc. with their own fonts and formatting, but I think that's more a part of the problem of bloated website design overriding browser-wide preferences.

For me ligatures are less important than syntax highlighting, but I do find them helpful - especially the greater-equal and smaller-equal signs are much more readable with ligatures, and that also applies when I read other people's code in my editor.

-> now needs more internal “rendering” than → does.

Same with ≡ vs ===