It doesn't just remove the need for an ICE engine, also the gearbox, fuel pump, fuel tank, radiator, exhaust system including catalytic convertor, etc.
An ICE engine is intrinsically complex to make, has many moving parts that wear out, is hot because it is inefficient at turning fuel into power. Plus, you know, the pollution.
A battery pack that holds sufficient joules is not intrinsically large and expensive any more than a 100 megabyte disk had to be the size of a washing machine and cost as much as a house, which was once the case.
Battery packs, even with current technology, cause little to no environmental damage, that is oil industry propaganda. Lithium and cobalt are fairly common, and all the cobalt we would ever need is accidentally produced as a side-effect of copper and nickel mining all over the world, that we would be doing anyway.