A quantum computer is not a fast computer. For nearly every task you care about - email, spreadsheets, video, games, most machine learning - it is dramatically worse. Slower, colder, more expensive, and it makes mistakes.
The two are not competitors. A quantum computer is a specialised accelerator, like a GPU, that a classical computer hands a narrow problem to.
The narrow problems where it may win share a shape: an enormous space of possibilities where the right answer can be made to reinforce itself while the wrong ones cancel. Factoring large numbers. Simulating molecules. Certain optimisation and sampling tasks.
That list is short, and it has gotten shorter over time - several claimed advantages were later matched by better classical algorithms running on ordinary hardware.
If someone tells you quantum computers will replace your laptop, they have misunderstood the machine.