I would say it's the cost of batteries. They're still somewhere north of $100 / kWh, most likely close to $150.
So range and cost are a trade-off. You can make a reasonably priced EV with a range of 100-200 miles, which would be entirely adequate for 90-some percent of use cases; commuting, grocery getting and so on, but it would suck horribly for any kind of road trip, so people generally won't buy that. They want something with the range they're used to, which means
at least 300 miles. But to get 300 miles of range, you need something like 100 kWh of batteries, which will cost $10,000 to $15,000 to make. That's an expensive fuel tank!
Tesla has built out an extensive network of Superchargers in the US, so at least for them, infrastructure isn't really a problem. They're located along major interstate highways too.
This one is at a "Truck stop" on Interstate 81 in rural Virginia. , it has ten or so charging bays. My wife sent me this picture earlier today when she stopped there for fuel. There were actually four Teslas looking forlorn while charging,
We stop there fairly often because that place has some of the cheapest diesel fuel anywhere our regular road trips. We've never seen more than one Tesla charging there, and more often it's none.
When we stop there, we get up to 700 miles of additional range in under 5 minutes.