You've got a fair few answers here, but none really go into why aero is important, or the actual differences between gas / Diesel engines and EVs. I'm coming from this from the viewpoint of someone who works with this stuff, though not an aero engineer.

The first thing here is that gas (petrol and diesel) and EVs are tested for range and efficiency in the same way, so aero has the same relative effect. The way that they're tested depends where in the world you are. In the US, it's the EPA drive cycle (exactly which drive cycle depends on the type of vehicle), most of the rest of the world uses WLTP, and China uses CLTC (which is basically WLTP). The point here is that the drive cycle (a specific set of accelerations and speeds, conducted over a set period of time) is exactly the same in any territory for the same type of vehicle. That means that it makes no difference if it's an EV or petrol engine. Therefore the effect of aero is the same for everything.

So from that, EVs don't benefit any more from aero than any other vehicle.

But....there't more to it. EVs, despite a massive increase in popularity over the last few years, still have a public perception problem with lack of range. Every mile (or km) you can get out of an EPA drive cycle test, gives you a better figure that you're allowed to advertise. But then....range isn't everything. Efficiency is what actually matters from a design point of view. For every Watt of power you can save, you need a smaller battery to give you the same range. Or you can have better efficiency and the same size battery to give you better range. It's a design balancing act of cost to the consumer vs what is actually desirable in market.

The other point worth raising is that the "aero" isn't just aero. Although it's common to pick up on a drag factor, like "oooooh this car has a 0.87 [cd] drag factor, isn't that great?", by itself it does't mean anything. You also have to look at the the aero uplift and the reacting areas to actually understand how aero is playing a part in efficiency,