MacBook Pro never goes to sleep
Back when the Aerial screen saver was first released there was a bug that would prevent Macs from going to sleep. The developer fixed that bug a while ago. If this is still an issue for anyone they should try download the latest version of the screen saver from the following link.

https://github.com/JohnCoates/Aerial/releases

For those that are curious. The screen saver was originally written to use AVPlayerView which by design keeps Macs awake when its playing a video. Aerial's developer rewrote the screen saver to use AVPlayerLayer instead, which does allow Macs to sleep when they are playing video but otherwise idle.