I am using a simple window manager plus also have no GUI file manager, so no drag n drop for me.
I dunno, but e.g. a number of people are using tablets instead of laptops nowadays? Basically on all sites that use drag&drop I always also see an upload button, it’s better to offer multiple ways, especially for essential functionality.
A lot of details like this we take for granted until we discover there are people who do things differently 