There's practically nothing you can do on a more expensive cart that you can't do on a modern console that uses disc media. Any benefits over discs that carts offered yesterday (no loading time, extra RAM) are non-issues today, and discs will always be cheaper to manufacture than cartridges.

The only new systems I can see still using carts will be niche media players like those little key chain ones that use to play music videos a few years ago that used DS style chip carts.

Other than that, carts will probably only be utilized by retro revival home brew projects for vintage game systems.