Would reusable rockets count. Technically it's an extension of rockets but it's still a new invention on its own

> 'Not extension' of an existing invention.

This doesn't exist. What was the last wholly new invention? Maybe the wheel or the stylus?

What I'd argue was the greatest invention of the 2000s, the iPhone, was built on the shoulders of research done by others for decades prior in a variety of fields.

Computer. Tv. Phone. Camera. Radio. Internet. Car. Bike.

Wheel and computer and camera are wholly new ones. Among many others.

I recommend looking up the history of the word "computer." (hint: it predates the thing you're typing on right now.)