Update for iOS Photos coming?

The feedback form for Photos iOS is here: Photos for iOS - Feedback - Apple

Plus if I use OS X and add a title or change the file name, that info is stripped out when it shows up in iOS.

You can still search for this information on your iPhone or iPad, if you sync your iOS device with iCloud photo library. The keyword, titles, filenames are syncing with iCloud, but just not shown in Photos iOS.

But you are right, the lack of visible metadata is a horrible limitation. I do not dare to delete or edit any photo from may iCloud Photo Library on my iPhone or iPad any longer, when I cannot tell which of two look-alike photos I am deleting, because I can neither see the filename nor the title or keywords. On my iPhone or iPad, I just view the photos, I no longer edit them.

When I purchased my iPad, I bought it, because it was a great companion on shooting trips. iPhoto on iOS had advanced editing tools, and I could add titles and keywords to my photos. Half a year later, iOS 8 made iPhoto iOS incompatible, and since then I had to find other uses for the iPad. It is no longer possible to use it to add titles and keywords to my photos when I am on the shooting site. I have to take a MacBook Pro with me and the iPad stays at home.

Nobody here knows what Apple plans to do with Photos in the future. (Or if a few do, they would not be allowed to tell the rest of us.) We just have to wait for Apple to tell us whether iOS 12 will have significant changes to the Photos app.

You may express your desired features to Apple through their formal feedback mechanism. They won't likely reply, and they may never implement your suggestions, but I'm told they do read all of them.

Meanwhile, those of us who care about being able to see metadata use third-party solutions. I use ones called Metaphor and ExifWizPro, but neither shows the Photos title or description, and what they do show is outside Photos.