is strap-on the future of keyboards?

Playing on a keytar has a big down side: your left hand is crippled!
So, unless you can play the entire gig with just 1 hand, you will find the keytar an excellent alternative. But I guess most keyboard players use both hands...

4 barriers remain, some are dwindling:
1) getting large keyboard functionality in a smaller package: a few decades keyboards required 5 roadies to move, now can be carried by one frail musician. The electronics get smaller, lighter and with good reliabily.

2) How do you get 88 keys in a wearable package? The "octave translator" on the 3 and 4 octave keytars is a fair compromise, but still impractical if you're doing a smooth run from one end of the keyboard to the other.

3) How do you get multiple ranks of keyboards in a wearable package? The size of the human hand the the design of 12 note octave keyboard will dictate a limit of compression. Remember the "dual neck" guitars which were tried and found to be a little unweildy? I've seen some weird two sided keytars, but that's almost learning to play an entirely new instrument.

4) The big shift for many classically trained keyboard players is learning to play without looking at the keys (or at least not all the time). How many years did it take us to be able to type these posts without looking at our computer keyboard? Also, keyboard players quickly learn that its ok to play the keys with a flat finger, rather than with "curved knuckles" (that our piano teachers beat into us!)

I doubt keytars will shrink to a "niche" item. They are just too much damn fun, with or without the "chick improvment".