It's sustainable, you just don't understand the manufacturing process well enough. Seeds of old trucks are planted in the ground which generate the next truck crop for harvest in the fall.
Not trying to advocate petrol cars because public transport and cycling are obviously the most sustainable means of transportation, but I fucking bet that a tiny 3 cylinder 1 litre petrol shitbox is more sustainable than electric SUVs... At least it can last more than 5 years on the road and be easily repaired.
Ordinary petrol or diesel SUVs are often piece of shit because they are too flimsy to off road, not to mention how inefficient they are. Electric ones are no different, except that they are built like an appliance that is going to go to a landfill after its warranty ends.
I know this is not an objective comparison, but I was shocked after renting and comparing Peugeot e208 and e2008 for a couple of trips. e208 is an ordinary electric compact car, while the e2008 is an SUV built on the same powertrain. Guess what? The hatchback is quick, nippy, easily maneuverable, while its fat cousin is sluggish, sloppy and uncomfortable due to its weight and height. Utter garbage.
As much as I hate SUVs, an electric SUV will probably have a lower carbon footprint than a small petrol car. Obviously the SUV is garbage for many other reasons, but generally speaking, ICE has a much lower energy conversion efficiency, and the oil supply chain is much dirtier than; even though per unit mass, lithium is worse, the sheer amount of petrol the ICE vehicle will consume over its lifetime will outweigh the production of the EV several times over.
The actual calculation depends on how dirty the power grid is in your area, or if you have solar panels.
Either way, I 100% agree that neither of these are good solutions and we should be pushing for public transit and bikes.