Are you suggesting that if we can't solve every problem simultaneously we should not solve any problems? It sounds like a step in the right direction to me. Hopefully this will spur steps to solving the other problems in other directions too.

We use fossil fuels to build an ICE drivetrain. Or we can use it to build an EV drivetrain.

Sorry, unless you back this up with data (that is, numbers), why should anybody believe your assertions?

Here is something that can support OPs claim. Car's are still manufactured with oil, all the plastic, the paint, the tires that comprise the vehicle are dependent on oil. A car requires a lot more oil to produce than people understand so until focus on materials is shifted the car production alone is still a problem.

Totally valid. It doesn't mean that until that problem is solved we shouldn't solve problems. I'd compare it to an anti gun-control argument I've heard. Roughly it's that some people who want guns enough will be able to get them, so gun control is useless because we can't stop all gun deaths at once. Which if flipped, is sort of saying that having less guns cheaply and easily available with more regulation is a bad thing.

Aside from the risk of a spill, What is wrong with using oil to produce plastic?