The default fonts are just plain awful. It's trivial to drop in a better font and make it indistinguishable from native.
Possibly a licensing issue as to why they don't include better ones by default as you have to bake it in? or they want to make the binary as tiny as possible by not using a bigger font file?
Possibly a licensing issue as to why they don't include better ones by default as you have to bake it in? or they want to make the binary as tiny as possible by not using a bigger font file?