iCloud was never designed as a storage facility for photos. Perhaps that is something that they will introduce in the future, but since there are so many other good services out there that do that kind of thing, it also may be that connectivity is the driving force here (think different?).
I guess we will all just have to wait and see 🙂!
Personally, I have found that using products that are the primary forte a particular vendor usually results in a happier experience for me. For example, I use Firefox because Mozilla started out in the browser business, and I think they are at the top of the heap as a result. Same with Amazon's Kindle product. I like the actual physical readers better because they are designed specifically for reading so really reduce eyestrain, I like the book selections better, and I find that they are typically less expensive than those from either Apple or Barnes & Nobel to name a couple. Amazon does a lot more now, but books is where they started, and they are among the best in the industry in my opinion.
I don't keep my photos in a cloud service, or I would tell you what I think about that as well, but I am very happy with the Photos App, with my Time Machine backup, and with my syncing back and forth between my Mac and iOS devices (which I don't even have to do with photos anymore because of the improvements in the way that the Mac Photos app and Photo Stream work together to get my photos imported automatically and almost instantaneously.) Still have to sync videos, but small price to pay for me 🙂.
But I have heard good things about Drobpbox, Amazon Photos, and Google Photos from others on this forum, and I always found Flikr to be a fascinating site, so hopefully you will find a happy home for your photo storage in one of those places!
Best of luck 🙂
GB