“Inspired by” is way more loose than “dramatization of historical events”. The former can be pretty much anything even loosely based on some idea, but the latter has a more strict set of rules, although still rather subjective.

Chernobyl was definitely a dramatization, not just “inspired by”. It really did tell the events much as they happened, only taking liberties in things that truly required it for the show to work as drama. Like one thing they did was replace what was a large panel of scientists with one character who made the points the panel did. Does that take away from the veracity of the events? I think not much at least.