I have a suspicion that text rendering when upscaled and in general plays a role.
If text is too small, tired. If it's too blurry, tired. Too sharp, tired. You get the picture.
Panel PPI density makes a difference with font configuration settings.
My Steam Deck, due to the small panel size has a higher PPI than my desktop monitor which has a higher resolution than the Deck's resolution. So what this has meant in practice for font rendering, is that on the Deck I am using subpixel rendering (the correct layout, this panel is not RGB) but without hinting, but when connected to the external monitor I have subpixel turned off and hinting is on. Anti-aliasing on for both circumstances except in some specific apps that I configured to not use anti-aliasing.
Need to know if scaling is going on, and then adjust the text size for your own eyes (which gets harder when you get older) and then know what PPI your panel is and adjust the rendering accordingly.
PS. While you do get used to any font over time, some fonts just are not as good as other fonts for legibility. This plays a role too. I also adjust the weight of the font as well depending on the display being used, e.g. phone. You don't want the font to be too bold, but you also don't want it to be too spindly. Don't want it to be too squat, or too elongated.. smh.
PPS. Oh, and the LCD color filter for subpixel for fringing removal? That plays a role. I don't like freetype's lcddefault for this. I use lcdlight instead which is more crisp.
