This is why the series hybrids don't really make sense. If you have to add an engine to generate electricity then it needs a fuel tank, a cooling system, an exhaust system, etc. By the time you add all of that stuff, you might as well just use that cost and weight to put in a bigger battery.
There is no technical reason you can't use an arbitrarily large battery to get arbitrarily long range, it's just that the incremental cost exceeds the incremental benefit for most people, so the current EVs are targeting the much larger number of people who don't actually need that much range. They're also supply constrained on battery production right now, so targeting the niche that requires a very large battery doesn't make sense yet.
This is somewhat what I would expect to eventually see out of a pickup or something that competes with a Chevy Suburban. You have a large vehicle, so plenty of room for batteries in the floor, which you also need to get reasonable range when transporting heavy loads. But then if you're not transporting a heavy load, the same batteries provide much more range than a vehicle which is trying to be spry and sporty.