There's no free lunch
Everything is a trade off somehow. Come up with a better powder that leaves no residue? Sure. Start by giving me (or a chemical company) a few hundred million dollars for design, testing and expirimentation.
There are practical limits to everything. As was mentioned, change the powder significantly, and you might have something that cannot be contained in the brass case and steel of a gun (or at least one of a size we would be willing to carry, use, and most importantly, buy!).
Powder is being impproved, over time. But the process takes time, MONEY, and brings limited results. We have better powders today than they did in the 1930s. But only in a small degree.
As to a laser, well, the problems with lasers are mostly, power (in a man portable package), the effect of atmosphere over distance, and their effect on those things most usually shot. Burning a small diameter hole through a deer, or a man (and cauterizing the wound in the process) would not be a good stopper, unless you nailed the brain, and did it in the just right place!
Caseless ammo has been under developement for around 40+ years, and hasn't been made into a workable proposition yet, although some developements show promise. If they do get it perfected (enough to use), I still won't buy any. I like handloading!