What if instead of adding more tanks of petrol, you added more trailers of batteries.

Because the energy density problem. A trailer of fuel holds more energy than a trailer of batteries for the same weight.

No matter how much battery you add, it's always possible to get more range with less weight in fuel, and with less diminishing returns.

Energy density is just part of the equation. EV's also can use regenerative braking and recharge when going downhill. That's how Tesla's achieve their mileage. Electric engines are substantially more compact and lighter than similarly powered ICE's, giving more mass and volume budget to add extra batteries.

In the specific case of trucks, in most places you can't demand a driver to do a 2000 mile leg on a single stretch and, with the required pause to rest, it's also easy to recharge. A limit of 700 miles should be considered a reasonable target for truck range on a single charge.

Airplanes are probably the place where internal combustion (or not quite internal, but still combustion, as turboprop and jets are not ICE's) will have a significant share for a long time. Even there, short haul small planes are already electrifying.