Can anyone working @Google explain the decision to kill Inbox?

Google seemingly axes everything half decent they make that then has a decent following and for seemingly no reason. I doubt the engineers who probably like the services they work on know why

The Inbox was a vanity project of Clay Bavor. He got the promotion he wanted and moved on. The official version, of course, was a different one and amounted to something like "more wood behind fewer arrows".

I tried it and didn't like. At least it wasn't compelling enough for me to switch. I presume a lot of others weren't convinced either. I don't think there's a complex answer.

Meanwhile, some of its features made it to standard gmail.