I've tried looking this up and never find a solid answer. Seems to be down to preference, but I'm thinking there has to have been some study around fonts and reading speed or reading comprehension, something that would help me pick a font?
I have no sources but I also read that some fonts are easier for people of certain regions (ex: people from Antarctica enjoy reading Arial font). Should I just end my search and try to enjoy my ebooks?
It's not an area I know deeply, but it's my understanding that certain fonts are more generally "legible" than others (for most people). This study found Arial and Microsoft Sans Serif to "be good and legible fonts" and Tahoma to perform poorly. But overall conclude that as long as people are literate, it doesn't make that much of a difference.
On a personal level, I do find certain fonts easier to read (especially for complex, run on sentences in journals) but when reading a novel a thematic font can help set the tone. It can even slow down my temptation to skim read and force me to focus on each word, which can be satisfying. So, it's part preference and part asking what you want the font to do for you - bland, familiar, accessible, easy to skim over? Arial is a good bet. Don't want people to fee like their in the office while reading your novel? Go with something else.
I find it hard on my eyes, but I think it's great that it exists for people to choose, especially for those who actually get a benefit from it. The best thing is to let people choose their own fonts everywhere. Yes, it might clash with some corporate profile, but fuck'em.
I always mess around with available fonts and try out the publisher font of available, but somehow I almost always land back on Bookerly, which is Kindle's proprietary typeface. It's just pleasant to look at and easy to read.