Who / How do decide to feature request or bug will not be implemented or fixed at the present time?

You can find the most voted status-declined questions form following list.

https://meta.stackoverflow.com/questions/tagged/status-declined

If you look at the list, there are highly up-voted status-declined questions…

status-declined tag used to indicates that the feature request
or bug will not be implemented or fixed at the present time.

As I know, lots of upvote means community likes that feature…..

So Who / How do decide to feature request or bug will not be implemented or fixed at the present time?