The Snap would kill at least 90% of humanity, probably more.

First, let's look at the immediate effects. Half the people on airplanes will, of course, be dusted... but a quarter of airplanes will lose both their pilot and their co-pilot. Those planes are all crashing, killing everyone on board, plus whatever they hit.

Everyone on a major road, or the sidewalk next to it, is dead. When half the cars on the road suddenly go driverless, everyone crashes.

Some households are suddenly entirely empty (half of all single-resident households, a quarter of the two-resident, etc.). In a few of those households, someone just put something on to boil, or started some other similar process that needs supervision. Expect a large number of fires to start, within an hour after the Snap. Plus whatever happened from all of those crashing cars and airplanes.

At this moment when all these fires and other emergencies suddenly arise all at once, there's half as many firefighters as there are supposed to be. What's worse, the roads are all cluttered with crashed cars, none of which will be able to pull to the side to let the fire trucks past. Without effective response from the firefighters, the fires spread, until whole cities are burning.

We're already well over half the population, just in that first chaotic day. And now we start looking at all of those supply chains that humans depend on for survival. Even if production (of everything) scales with the total population (but it won't, because there are some specialists who hold key skills and information only in their heads), it's not all going to go where it needs to. Some people, in some places, starve. Or die of pre-existing health conditions, because their caretakers are dead, or they can't get their essential medications.

There's going to be a general breakdown of law and order, meaning a lot more violence. That'll kill more people. And most people don't know what's happening-- What if the high brass in a few nuclear-armed militaries decide that the Snap was a pre-emptive attack of some sort by their enemies? Missiles will fly in retaliation, and there go more people.

The human species would survive. There are a few people out there who are genuinely prepared to deal with cataclysm (hint: Almost none of the "preppers" are). Half of those people will stay undusted, and they'll rally a few other survivors. But it'd be very grim indeed.