we're gonna get quantum propaganda now!

AI can take your job even faster! Also eggs cost $50 now!

I don't understand anything about quantum computers. Are they useful? What do they do?

there's some quantum versions of algorithms that scale better than the digital version. ranging from quadratic to exponential speedup. Notably very fast at breaking currently widely used encryption.
We are only saved by the fact quantum computers don't have the required processing power to be feasible to use yet.

There's some encryption algos that are thought to be resistant against quantum attacks but due to the above this isn't actually proven yet, so currently any "post-quantum encryption" is currently a marketing buzzword with nothing behind it.

They're not a silver bullet, but they have their usecases. Quantum internet can be very interesting due to instantaneous communications. But for general purpose computing, a hybrid approach of quantum+classical is most probably the way to go. There's limited use cases for quantum computing in general computing.

Quantum internet does not allow instantaneous communication. That would violate the no-communication theorem. It's physically impossible.

Well yes, not instantaneous instantaneous. But near-instant as far as I know. Much much faster than current speeds.

It can't be faster than the speed of light and radio already travels at the speed of light.

So entanglement and teleportation aren't practical for this?
the max travel speed might be light but the time to process that information and react to it can be reduced. I'm not sure tho. But I strongly remember reading articles about this.

Entanglement cannot be used to send signals faster than light, and when "teleportation" was named, the model the physicists had in mind was Star Trek style teleportation, where you scan the original copy in a way that is destructive to it, transmit that information elsewhere, and then reconstruct it. That transmission step is still through a classical information channel so it cannot be faster than light. It was not named that way after magical fantasy teleportation where something just disappears from one location and instantly appears in another. It was an analogy to how the algorithm works: quantum mechanics forbids cloning a state, but you can semi-get around this by cloning it in a destructive way, so that the state you never have two systems,at the same time, hold the state you are trying to copy.