Most light themes I’ve encountered don’t seem to grasp the concept of ‘contrast’. I bet if you were to survey light theme users, you’d find that most of them have nonstandard/weird settings on their monitors. Chrome dev tools, Xcode, and Visual Studio’s light themes are all great though, as they have proper contrast and don’t look like rainbow vomit.

But one other issue with light themes is that for some people (myself included), it makes ‘eye floaters’ stand out more. I’m fortunate that my case isn’t terrible, but I can see it being a serious problem for some people, especially older developers.