I guess it's just one more visual marker, perpendicular to e.g. colors so you get twice the possibilities. Whether italic or bold or colors or anything, I find

I guess it's just one more visual marker, perpendicular to e.g. colors so you get twice the possibilities. Whether italic or bold or colors or anything, I find that too much visual marking is bloat, unecessary cognitive load which overemphasize syntax, detrimentally to flow — it's harder to gain more perspective when you're kept so 'in it'. Good typographic rules very much apply to code as well. I personally think ~3 to 7 marking variations are usually enough to convey a general paradigm.