You can't build a house without nails and screws, though.

Sure, if you're only writing a small script, you might not need tests at all. But as soon as that program evolves into a system that interacts with other systems, you need to test each component in isolation, as well as how it interacts with other systems.

So this idea that unit tests are not useful is coming from a place of laziness. Some developers see it as a chore that slows them down, instead of seeing it as insurance that makes their life easier in the long run, while also ensuring the system works as intended at all layers.