Yeah, they can definitely be jarring at first. But if you use them for a little while in a terminal that supports them (I use kitty[1]), the non ligature font will look jarring instead. I'm not so sure about using them for online code samples, though...
Right- I did look at them when they first came to my attention and I do like the look. If I were more of a fan of terminal customization I would probably give them a go. But it's weird to see them in code samples online.
I remember when I first was looking at them, I realised that they aren't even all consistent. I think it was the the "<=" ligature. <= can either be glossed as a left arrow or a less-than-or-equal, and at least one font decided somewhat inexplicably that it was an arrow. These fonts have no idea what the semantics are of what you're actually coding (since they're just ligatures) so insofar <= always means less-than-or-equal then you're fine, but if you find some language where it means assignment you'll need a different font!
[1]: https://sw.kovidgoyal.net/kitty/