The Hero Shooter genre isn't dying as much as its consolidating. It is a very competitive market and for a new entry to be successful it has to bring something new to the table. The developers also have a lot of work on their hands to try and maintain that. Games like that sometimes do well at first and then end up abandoned by the player base shortly there after.
Concord shit the bed because it did everything it needed to on a sliding scale of mediocre to bad. It was Temu brand Overwatch for chubby chasers.