I think Dropbox ticks all 4 requirements. That is what I use. Their ios & android has automatically uploaded my camera photos for years. I move some into spec

I think Dropbox ticks all 4 requirements. That is what I use. Their ios & android has automatically uploaded my camera photos for years. I move some into specific folders to share with family via their photo album (gallery) link feature. As its dropbox, it is all just files and synced to my laptops all the time as well. The only issue is if you like their gallery feature. I do, some may not. They recently closed their Carousel alternative. https://photos.dropbox.com/app/timeline https://photos.dropbox.com/app/timeline https://carousel.dropbox.com https://carousel.dropbox.com