Technically empty batteries weigh less than charged batteries.

Not that the difference is significant enough to tip the scale though.

And let's not forget that fueling your car requires a tank, a decently sized pump and 2 minutes of your time. A quick charge will hopefully charge your battery to 80% in 30 minutes, while giving you less km and running 300kW of power through hefty cables and big transformers, consuming the amount of energy that a family house consumes in a few days.

(And yes, battery manufacturing and disposal consume enormous amount of resources)

Electric and gas have different situations in which they shine. Gas/diesel engines are just a bunch of steel and some control chips, optimized in more thana century of technological development if we couls develop carbon neutral fuel, electric cars would not be needed. Unfortunately, it woulf be difficult to do at scale of current fuel consumption. More (electric, battery-less) public transport, less road goods transportation, more nuclear, electric for vehicles that move 100% of the time (delivery and logistic vehicles) and carbon-free fuel for other kinds of vehicles (personal transportation) is a good balance, in my personal, ignorant, armchair opinion.

How do you think about hydrogen cars? They have better fuel density, and hydrogen is renewable.

I'm sorry but I'm too lazy to dig up links to back up my claim. But you are correct in that electric vehicles pollute far more being produced than combustion engine cars, however the electric vehicles gain that back over it's lifetime if your charge from mostly non-fossil sources. The figures I have read says that over the lifetime of a car, electrics output 70% less CO2 than combustion cars, and that includes the production of each of the cars.