That would be http://steamcharts.com/app/375230 . Dwindling numbers of people playing would be the logical explanation to longer queues. Which is a nasty downward spiral - longer time to get games make people give up on finding games, meaning fewer players, meaning even longer waiting times... EDIT: sorry if I'm not allowed to post external links, but that one is 100% legit/safe and 100% relevant for the thread so please keep it if possible.
overwatch: not because random reason, i look at the EC discord and many players are playing overwatch also djpenguin for example.
Go to the community hub for EC. It usually tells you how many people are playing on the top right but sometimes it doesn't.