If we're talking about the "next" thing and not far future fantasy or even the next disruptive tech that will upset the last 100 years or so of status quo, then I predict it will be firearms that are easier to manipulate for most people.
Most people cannot rack the slide on a striker-fired pistol. Even after being trained in some techniques to do it more easily, most people cannot do it easily at all. When I say "most people," I do not mean most gun people. Most people includes women, elderly, adolescent and teen boys and girls. The fact that it takes substantial grip strength and that a physically violent action is essential to the best technique for basic, fundamental manipulation of the most popular and common pistol type is a major barrier to expanding market size. If we're just talking about the "next thing" that will be sold to the same guy who already bought a Hellcat, a P365, a G43, a Shield, a G19, and on and on, then it will just be more of the same.
It's true that the Shield EZ does attempt to address this issue, but I am not convinced that it does so more than the Glock addressed the shortcomings of the Beretta in 1986. Remember that I didn't claim this thing would disrupt the status quo of the last 100 years. Back in 1986, it wasn't immediately evident to most people what the virtue of that change was. So I don't expect the Shield EZ will be very much more popular than it already is. What I do think is that these and other design features and innovations that make fundamental manipulation easier will be necessary for growth in market size.
The 9mm EZ M2.0 doesn't actually have any innovations that are unprecedented. It features a hammer-fired action, grip safety, single-action trigger, and single-stack magazine. The 1911 has all those things. But the EZ is a package that more people today will find amenable to carrying. Remember that I didn't claim this thing would disrupt the status quo of the last 100 years. One of the possible faults of the EZ is the light, crisp trigger that may be flattering to a novice's marksmanship, but could be a grave liability in a serious incident:
https://www.forcescience.org/2004/12/can-you-really-prevent-unintentional-discharges/ Would a hammer-fired gun with an easy-to-rack slide but a Kahr-style DAO trigger be better for a large portion of a growing concealed carry market to carry?
What I believe are the "next" things are:
handguns that don't have barriers for most people to manipulate them
handguns that are less likely to help a growing market of carriers to screw up under stress
handguns that will help that increasing population of carriers to make good hits
The key to that third criteria is training (not lighter, shorter trigger pulls), and the key to training in as far as the handgun itself can help is my first point -- not to have ability barriers. Getting more people to train is a much bigger problem, but not one that a handgun design by itself can solve.
I think there are other features that are proven to help people make good hits, such as low-recoil cartridges (that are necessary for the kind of <20 oz guns that people are willing to carry) and better sights or optics. I think those things are already here, and they will continue.
