GTK 4.14 is set to be released soon, featuring new renderers with improved support for fractional scaling. This means you can now use scaling such as 125% instead of ‘Large Text’, resulting in better font rendering. The idea behind these new renderers is to optimize for either uniform spacing or crisp rendering, depending on font options. While subtle, the differences between old and new renderers can be seen in details like the horizontal bars of certain letters. Overall, the new renderers in GTK 4.14 aim to provide crisper font rendering, especially with fractional scaling. Give it a try and share your feedback. No subpixel rendering is used in GTK 4 due to the lack of component alpha in compositing.
https://blog.gtk.org/2024/03/07/on-fractional-scales-fonts-and-hinting/