I am one of the converts from dark mode to light mode. I usually prefer(ed) dark mode but my experience has shown me that I end up having eye strain due to long hours of dark mode exposure. This is also prominent when I have to look at the world outside my monitors.
Apart from that I’m also challenged with configuring every application to work with dark mode in a pleasing way when most of them default to using light mode. Most applications by default are designed with light mode in mind (discord seems to be an exception). This is especially highlighted when I have to use Firefox and I’m blinded by the light. Even though darkreader exists for the browser, I find it inconvenient to modify every application/tool that I use to work consistently with specific themes/colors, which in turn I have to keep an eye on if things work/break over time and whether or not the theme is maintained. The time invested in having a consistent theme across applications is a rabbit hole I wish I had not pursued. FWIW, I like gruvbox and atom dark themes for my dark modes. MS Teams is another abomination where I cannot love the dark theme in any sense. Discord has done it right though, that’s the only application where I use Dark mode. On my phone, it’s easier to use light mode when I’m outside, with dark mode I have to tune the brightness to the maximum. There is definitely a reduction in readability with dark mode than light mode in an external environment.
The solution I use is night light in my OS which makes my screens warmer by sunset and back to normal by sunrise. You can do this by default in KDE Plasma and Windows. For other linux distros there is redshift. To make myself comfortable to work at night with light mode, I make my room bright enough to avoid my monitor being the only source of light in the room.
Following are some reddit comments which have echoed my thoughts more succintly than I could put it.
I’d say, stick with the default. Like you found out most themes are just not 100% right. The default themes have a lot of thinking behind it.
On my desktop I run debian/plasma with the breeze theme because it looks great on plasma and gtk apps. And on my laptop it’s ubuntu/gnome with the ubuntu theme.
Both themes are easy to look at for hours and hours. Oh, and I really do not like dark themes. They might look nice, and then you open a document or a webpage and your eyes start to bleed ;-)
Always stick to default themes because they are fixed and updated with each upgrade. Those community/amateur themes are pleasing to eyes but they lack continuous maintenance and deep testing.
After spending a long time at the dark side, I’m older and wiser now to embrace the light.