For devices that require more power than that, there's three-phase current, also called "krachtstroom" (= "power current") in Dutch, which, from what I understand, can deliver up to 19kW (though intuitively I'd expect it to deliver 3 x 3.5=10.5 kW). We have this for out induction stove. Getting it was a bit involved, because it turned out our house had only a single 35A connection, whereas 3 (usually 3 x 16A or 3 x 25A) is more common, so we had to have our electricity connection upgraded.

Still cost less than $6000, though, and many Dutch houses already come with a connection that can handle this. Though that might not be true for other parts of the world.