That version of JIRA could still easily be configured to be awful. That's the main problem with JIRA - the power to actually configure it to be sane is always reserved by a few people who don't want to bother, don't have time and don't care because they aren't really using it every day.

Well one of the problems anyway. It's also unimaginably slow, and has weird limitations like issues can't be parents of other issues.

The non-existence or non-availability of recursive features, like an issue being parent of an issue, or in Slack a thread being started inside a thread and so on, to me usually indicates, that the developers of the tool are afraid of recursion, and have never learned how to implement this easily in a database, used a programming language that easily deals with recursion, and don't know how to deal with it in other languages. They tend to think "it's too complicated". It's usually just a silly lazy excuse, but here we are, with tons of inflexible shitty tools.