If you look at the steam statistics mount and blade is actually more popular than it was in 2012-2015 in terms of average players. The players base has been fairly consistent from 2016 till now, according to steam statistics. I still see weekly events that reach 200/200 players. I see more regiments that want to do a gf than I saw a year ago. Either we lost players to native or other mods that also do events around 7 gmt or the game is just doing fine. Maybe the competitive scene has been lacking a bit, but i still see enough gf teams.
So the mount and blade isn't really dying, maybe NW is, but in my eyes atm it isnt really dying.