I think it differs a lot between people and what they prefer.

Me myself I have very hard reading applications with "Dark mode" GUIs I can hardly read the text, very strainig for my eyes, so for me I need a "Light mode" GUI (I have normal vision).

But it could very well be the other way around for other users so I think one needs to have both options and be able to configure what is best for the individual in each case.

It is very disturbing to see that some companies only offer their applications with dark mode (especially the photo related apps). They think they "know" what is the best for the users, but they don't. They may also think it is a more "modern look" for the GUI, that might be true but that is not the same as it is the best for the user or what the users want.

I only buy apps that have the option to switch over to a "Light mode" GUI. If they only provide a "Dark mode" GUI it is not for me.