[mseepgood]

Why do Duplo trains replicate steam engines instead of contemporary railway technology?

[bombcar]

They also have one that imitates a diesel loco: https://www.lego.com/en-us/product/cargo-train-10875 but it's out of stock.

The train base is actually the same as the Duplo truck base so you can put a truck body on it if you wanted.

And as to the answer, steam train go Choo Choo.