I read mainly on smartphone, because I feel it hurts my eyes less. Maybe it's because or luminosity, anyways my computer screen feels way more tiring after a hour of reading than a smartphone.
If I had only a smartphone I'd probably read manhwa instead of manga. It's easier on your eyes (on a phone) and is as much designed for phones as for computers.
I personally view the desktop version for checking updates and finding new stuff to read but i prefer to read it on my phone as i can do so while lying on my bed.