My iPhone Photos app uploads photos and edits extremely slowly. Can I fix this somehow?

I frequently will notice that a handful of photos on my iPhone will still not have uploaded to iCloud for several days after the photos were taken. I often notice a message at the bottom of the Photos Library indicating, for instance, that it is "Uploading 23 photos" or "Updating 7 photos to iCloud", with a progress bar that suggests it is making progress, but not actually moving much (or at all). Sometimes the same 7 photos will be indicated as being "updating to iCloud" each time I look at the app over several days. There doesn't seem to be any problem with my WiFi connection, or with using the internet in general, and my photos and videos are not atypical in size -- usually 1-5 MB Jpegs or maybe, on rare occasions, a video that's fairly large, but not something I would expect to take more than a few minutes to upload, at the most. I feel like there's some kind of glitch happening that might benefit from "resetting" the library, somehow, but I don't know how to do this.

It does seem like this would be a major problem if I used iCloud photos for work purposes, when you might need to access recently taken photos in short order on your desktop, and it's hard to imagine that apple would implement a system that couldn't be synced in a reasonable timeframe. Is there something I'm doing wrong, or some fix that I should explore? The online questions I've found usually refer to an initial library sync with a new device, or upon activating iCloud photos for the first time when one's library is huge. Mine, is large, but the problem I'm referring to is only in regards to routine, daily photography that I wouldn't expect to require more than a few seconds to sync properly.

I have plenty of space on my devices, and plenty of available space on my iCloud account (I'm subscribing to the 2T level). I've never used PhotoStream, but I don't expect that would be useful for those who are subscribing to iCloud Photos and expecting to be able to access their whole library from any device. Suggestions?