It has warnings that steer you away from idiomatic Python towards less idiomatic Python.

Idiomatic Python favours EAFP (Easier to Ask Forgiveness than Permission) over LBYL (Look Before You Leap), so you might write something like this when using TypedDicts:

    try:
        foo = bar["baz"]["qux"]
        ...
    except KeyError:
        ...

Pyright warns you about this and pushes you to write this:

    if "baz" in bar and "qux" in bar["baz"]:
        foo = bar["baz"]["qux"]
        ...
    else:
        ...

They identified this as a bug and fixed it, then changed course and decided to reinstate the behaviour. So if you want to write idiomatic Python, you need to disable typechecking TypedDicts.

— https://github.com/microsoft/pyright/issues/1739

Now if this were a linter then I would understand. But a type checker should not be opinionated to the point of pushing people not to use idiomatic Python.