First it was iCloud, then it was Dropbox, and now I exclusively use Google Photos.
I switched because Google's sync is faster, its grid layout is cleaner, and because Google has built in AI that arranges your photos by faces, places, etc. Google Photos also automates some of the stitching so it makes video montages and applies filters for you. The result is hit or miss, but you can save what you like.
And now Google Photos is even better. It'll delete your photos off your phone after syncing them to the cloud so you don't have get that 16GB iPhone nightmare that says “storage is full.” Previously, you’d have to manually delete photos from your library. Not anymore.
Like I said, I’ve been raving about Google Photos for a while. And it’s only going to get better, especially as it consolidates technology like Motion Stills into one central Photo app.