Sub-pixel antialiasing rules
I'm not sure what happens there. Looking at the rendering of "considerations" in your example, the "cons" looks like what you get when you do crude sub pixel anti-aliasing, without applying the necessary "fix up" to make it look good. But then the "der" in the same word looks like there's no sub-pixel anti-aliasing.

You can find a good article about how good looking sub-pixel anti-aliasing works here https://www.grc.com/ct/ctwhat.htm and for the "fix up" part here https://www.grc.com/ct/freeandclear.htm and here https://www.grc.com/ct/cttech.htm

What it comes down to is: if you just compute the R/G/B intensities by calculating the covered area for each sub-pixel, the resulting color fringes are very ugly/irritating. To fix it you have to apply a horizontal blur/low-pass filter to the sub-pixel image. The result is an image that's less sharp but also has far less saturated colors. I.e. something like your "Check you" example.