The best MTB gloves feature synthetic leather palms because the material efficiently wicks sweat without compromising grip and is resilient against hands-first slides in the dirt.
Many brands add patterns and silicone details to the palms, which may provide a marginal increase in purchase depending on the glove and your chosen handlebar grips. The staying power of the silicone details is also brand-dependent, and quite often these will wear away well before the gloves are ready to be retired.
Most gloves also feature touch-screen-friendly thread sewn into the tip of thumb and index finger which work with varying levels of success.
Pro Tip: if you can’t get your touchscreen to work with your gloves on, lick your finger! It sounds gross, but it works without fail and is considerably more efficient than using the tip of your nose or trying to rip your glove off to answer a call.