This stuff is very subjective but for me if you have to use something like jsx where there is a lot of structure/punctuation then dark mode does make it easier

This stuff is very subjective but for me if you have to use something like jsx where there is a lot of structure/punctuation then dark mode does make it easier to spot that mismatched bracket. But overall I prefer light mode because I can scan across pages of code much quicker and find what I want. The broader layout is more apparent to me. For the same reason I definitely prefer to read long form text in light mode. Which means that I would have to switch between dark and light mode anyway (even if most web content was switchable to dark mode). So it's light mode for me with at most #F5F5F5 background for code