Probably a lot of those that have remained open will also stay that way, because they are (1) fake job ads, or (2) job ads of companies, where you don't even reach a human soul during the application process, and the companies don't realize how broken their hiring process really is, or (3) job ads of companies, who have so unrealistic idea about what they are looking for and what they themselves are actually offering to attract whomever they are looking for, that almost no one applying meets the criteria.

Probably I also forgot some more categories of crazy hiring processes in my enumeration.