Growth rarely lasts forever, and Snap had more employees than generally considered reasonable with such a single-purpose app. I'm surprised they aren't laying off more engineers though, personally.
Snapchat want to show the maximum of sponsored contents to the users (BTW it took me a week to stop swiping right by reflex after the update) and users just want to send pics to theirs friends.
I know that my usage of Snapchat is anecdotal. If anyone has data on the percentage of users that voluntary look at sponsored content, I'm interested.
Yet, with this latest update, they removed the stories/sponsored mixture and banished sponsored content to its own screen. Once you get over the habit of swiping right, you never have to open that screen again... if anything, they reduced the amount of sponsored content I see.