Yep, sticking plasters over problems describes it perfectly ;) Many refactoring attempts, but never completed, because JS makes it really hard. And yes, code quality is bad. Most of it was written by people who never wrote JS/HTML before, then it grew historically and here we are with this mess.

But besides TS being very helpful in a messy code base, personally I would also always start a new project with TS. For me the benefits greatly outweigh the minor annoyances (I really see them as minor)