I wouldn't call them useless blobs.
I agree that most of them don't have effective impedance at 2.4GHz, but they are designed to suppress frequencies below 1GHz, which is the usual source of radiated emissions or immunity problems. They prevent the wire leads from acting as antennae. Again, they are very common and well understood in electronics.
Again, they have a specific purpose on when/where they should be used. Even if applied when not needed, they will not cause any problems.