99.99% of bug reports do not

You're lucky if there is an accurate description of what produced the bug on the customers' specific setup at the time of reporting.

well then closing it with inactivity is fine.

Quite often reproduction information will only reproduce the bug in the customers environment, hence there is a lot of incomplete state on what is actually causing the problem.

It's pretty terrible in enterprise because there is so much 3rd party crap touching things it shouldn't that love to cause fun problems.