anyone that says "just use google takeout" obviously hasn't gone through the effort. i have about 178GB of data and they were all delivered in 2GB zip file chunks, many of them got corrupted, or never even sent over. i extracted my stuff when you could still tie google photos to google drive and even then each photo/video file ended up having 3 files, something for .json, something with exif tags in it and then the actual picture/video itself, it was an absolute mess.
if i know there's a service that will preserve the file 100% and it's easy downloadable then i would use it, for now, i'm extracting everything through iCloud.com and it seems to work perfect (much better than saving files out of iPhotos on mac directly). after everything is backed up to external HD i'll turn off the syncing on my local phone.