Whilst all this talk of quantum entanglement and superpositions sounds more like something out of a bad sci-fi film you may be surprised to learn that such computers already exist. In fact you can even access one made by IBM via the cloud.
Indeed, Google back in 2019 even claimed to have reached “quantum supremacy” meaning their quantum computer was able to perform a task which a conventional computer would not have been able to do at all or would have taken it thousands of years. IBM have since disputed the claim but there is no doubt that the tech is making great strides.

That said, whilst such real-life computers are incredible feats of engineering we are still far away from actually having useful quantum computers that reach even a small part of their potential.
The key issue still to be solved is that Qubits currently are very hard to keep in a quantum state as they are incredibly sensitive to external interference meaning even the slightest noise, heat or electromagnetic or other interference is enough for a Qubit to lose its quantum properties.
Qubits therefore need to be heavily protected from any interference and indeed some Qubits need to be kept at temperatures which are 250 times colder than deep space in order to keep them stable which obviously leaves the prospect of a quantum smartphone out of reach for the time being.
Whilst these issues will hopefully be ironed out in due course there is a long way to go. Indeed, it may be the case that quantum computers are never actually available for public consumption the way traditional computers have invaded our lives.
In all likelihood quantum computers will remain behind closed doors in the domain of big tech/finance companies and governments around the world for the foreseeable future but despite this when they do come of age their impact will be hard to miss.