For me my preference toward dark themes increased through the 2000s along with my need for syntax highlighting as I started writing more complex code. With light themes, syntax colors don’t “pop” nearly as well, giving me fewer visual anchors and making my eyes get lost in the code a lot more easily.

That said, I’m not fond of super dark or pure black-based themes and prefer those with a 75% gray background (with 100% being black) or thereabouts. With pure black themes the code pops too much and it feels like it’s all vying for my eyes’ attention at once.