Saying "dead game" is utterly nonsensical (more than usual) in the case of NASB - this isn't a team or battle royale game, it's a platform fighter focused on 1v1s, it doesn't take much work to find someone to play with on a Discord or forum and is arguably preferable to anonymous quick play even if it were active. It doesn't matter how many people are online at once as long as there's someone to play with.