They'll surely be available as a specialty item, but cramming a power supply, emitters, and heatsink into such a suboptimal package only makes sense for legacy compatibility.
Replacing a "light bulb" will seem as weird as replacing the backlight inside your laptop. Obviously a technician can do it, might even make sense to pay for that rather than buy a replacement for the whole unit, but it's not something regular people do themselves.
For more sophisticated users, AC/DC power conversion, power regulation/dimming, and the LEDs themselves can all be separate components. This allows more customization, and the possibility of replacing individual components when something fails.
Personally, I've been using Viltrox brand photo/video lights for interior lighting lately. These combine two sets of LEDs in different color temperatures with dimming/regulation, and an external AC to DC power supply. These have much better color rendering than most consumer stuff, and I like having adjustable color temperature. The bigger ones have remote controls, so hanging one from the ceiling is possible while retaining access to all of its functions.