I'm guessing between some of the Blizzard announcements and Apex, it's really hurting OW.  I always had several groups lingering around on a friends list but now there's lucky to be 1-2 people even at peak hours.  People were grumbling about OW for a little while now, no particular reason, everyone seem to have their own list of complaints so I don't think OW needed much of a push for some of its player base to move on.  
I always like OW and hate to see it go down without much of a fight.  Jeff is quiet, Blizzard only announces ignorance, and the people are deciding to play other games.  Shame this would happen to the studio formerly known as Blizzard.