Eventually it will be thin enough to have multilayered screens which will add additional depth to images which will create a 3D display. Similar to Looking Glass tech. Parallax will be a feature, not an issue for multiple perspectives as with typical glasses free 3D. The effect will be like looking through a window as they stack multiple 4k or greater resolution screens to provide depth/volume.
For automotive use they can put a layer of display on the windscreen to provide an overlay that can be used for AR navigation, displaying road warnings like speed limits, low-light vision enhancements, oncomming headlight dimming, among other capabilities. A layer of per-pixel dimming zones will enhance contrast and address the issue of wash-out without obstructing view.
For a phone with front-facing stereo cameras the display will allow for 3D video calls. I expect there to be phones released that have a see-through display, mostly gimmick early stuff that are basically nothing but an empty bezel ring.
The most immediate and apparent use case is a flex on the poors where your TV just “disappears” when you don’t want the looming presence of the nightmare/fantasy rectangle obstructing your view of the accent wall or art behind it.
I expect there to be phones released that have a see-through display, mostly gimmick early stuff that are basically nothing but an empty bezel ring.
Probably not anywhere in the near future, unless we’re talking a huuuuge bezel. You’re phone isn’t exactly empty space inside so you’d either need those to be transparent as well, or you’d need to fit them all one the bezel… so either you’ve got a big bezel or terrible battery life, probably :P. This is all speculation of course. Frankly, I could only really see a company doing it as a publicity stunt because I can’t imagine such a phone would be… good? Cool, yes… But having a transparent display sounds horrible!
Technically there are phones that utilize “transparent” screens right now, for things like under display cameras. So, there’s definitely use cases for the technology, and cool stuff you could do with it, but I’m not convinced you’d want a fully transparent display in a phone. Maybe headsets or glasses or something.