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.