I see continued interest in both compact and sub-compact pistols for the forseeable future, not to mention full-sized pistols or in between.
A typical "compact" or "sub-compact" pistol is about 4.5" tall at the grip, compared to about 5.5" for a full-sized pistol. A "compact" barrel is typically about 4", compared to about 3" for a "sub-compact". A shorter grip is somewhat easier to conceal in a belt holster than a full-sized pistol, regardless of barrel length. My personal favorite for easy concealment is a SIG P239, with a 3.9" barrel and a 5.1" grip height - in between.
A sub-compact pistol is more likely to be suitable for pocket carry. In my experience, a Springfield XDs (3.3") is about as large as practical for pocket carry. A Glock 36 is nearly 1/2" longer, and too big for pockets in casual or dress pants.
You must be careful selecting an holster for a sub-compact, so that the grip extends high enough above the belt to allow a quick, reliable grasp. You need about 2" clearance. The longer frame of a compact or larger pistol moots this particular objection.
A short grip is no harder to shoot, in general than a longer one. The main disadantage is lower capacity. Most of the recoil is taken up by the web of the thumb. The lower fingers help in recovery from muzzle flip, and in heavy calibers, torque control. In that regard, I can shoot a short handled (boot grip) .44 Magnum, but notice that the gun twists 30 degrees to left. A lesser effect occurs with .45 ACP (noticeably an XDs), and much less with .40 or 9mm, or even a .44 Magnum with a full-sized grip.