Menachem, two things:
Shu”a (OC 307:15) doesn’t say that reading novels, stam secular books(not chochma) is a waste of time – rather it’s a violation of moshav leitzim and al tifnu, potentially assur medeoraysoh. The mishnah berurah hrings rashi who says that al tifnu means do not go after that which you do on your own, without serving Hashem.
Captions are based on a gemara which says not to read the words underneath figures…i forgot the reasom, might be because tou might come to writing.
But the poskim say exactly that, that you may not read captions on pictures based on that gemara; it’s in every shabbos halacha sefer; not a machlokes about it as far as i know.
Reading the articles is an entirely different question. There was a special gezerah on captions…reading literature depends on what’s being read.