It has them, but you can't use them from a single-file script. You have to set up a pyptoject.toml, create a venv and then pip install . in it. Quite a lot of faff. It also makes some things like linting in CI way harder than they should be because the linters have to do all that too.

With Deno a single .ts file can import third party dependencies (you can use any URL) and Deno itself will take care of downloading them and making them available to the script.

Some other languages have this feature to certain degrees. E.g. I think F# can do it, and people are working on it for Rust, but Deno is at the forefront.