There’s a good 3blue1brown video that walks through the actual math they can perform, which does a lot to temper expectations about what they can accomplish and how much of an improvement they would be over digital computers for certain types of problems.

Here’s the YouTube link, or search for “But What Is Quantum Computing? (Grover’s Algorithm)” on your preferred front-end: youtu.be/RQWpF2Gb-gU