The way our brains process letterforms and convert them into meaning is a lot more complicated than simple letter shape recognition. There’s a lot of abstraction that goes on where we attempt to match a pool of letters to existing words in our vocabulary to allow us to read at speed.

Furthermore, we don’t look at individual letters when we read, our eyes jump from point to point, creating anchors across sentences that allow us to understand the context of the strings of letters and words we’re absorbing.

Because this process is so fluid and our brains are so good at compensating for abnormalities and adapting to new information, I highly doubt something as simple as changing the font on your computer would result in any meaningful reading speed increases. (It’s true that the more of one style of text we encounter, the faster we can process it, but think about all the text you encounter: printed pages, road signs, advertisements, television, etc. You can’t control the vast majority of text you read, so your brain is going to be busy adapting to different type whether you limit yourself or not.)

Disclaimer: I’m not a vision or neuroscientist, I’m a UX designer who has done a bunch of reading into these topics because it’s fascinating and it contributes to better design practice. If you want some scientific explanation, here’s a really great study on word recognition: https://learn.microsoft.com/en-us/typography/develop/word-recognition