[necovek]

As a Serbian speaker from Belgrade, I'll understand a Croatian from Zagreb better than I'd understand Serbian spoken in Pirot.

Basically, the point is about what defines a language as a distinct one.

Grammar is pretty much the same with one standard preferring one form or the other (eg. infinitive vs "da" + present). Vocabulary is over 90% identical, though I am sure top 500 words in both spoken dialects have a larger discrepancy. Alphabets are different, but they are almost bijectively mapped (only differ orthographically in digraphs like NJ/Nj/nj where Cyrillic has only Њ/њ), and you may have missed it, but Serbian population actually uses Latin script for >80% of all Serbian writing.

The article mentions a push to differentiate languages further, probably most evident in Croatia in early 90s.

But three students in Bosnia speaking identical language (grammar/vocabulary thougj the script might differ) of 3 different nationalities would officially claim they speak three different languages. If you don't see the absurdity in that, that's up to you.