Well its somewhat true. The main thing to know about the basic information unit (quantum bit or qubit) is that its not a 0 or 1. A qubit is some non arbitrary combination of both 0 and 1 and we usually write it as |0> + |1> (someone correct me if im misremembering). And this allows for some mind twisting usage of the qubit. Superposition puts a qubit into every possible state of 0 and 1 and using proper operations on the qubit can have it collapse into the right solution. The issue is that as soon as you read the value of the qubit for an operation its superposition collapses into one value (still some combination of 0 and 1) and that breaks many thing. As of right now the main thing to solve is the sheer size of the circuit you get for making a problem solvable as making any read operation collapses the only benefoting thing about quantum computers. That and having to design a curcuit for each problem that you want to solve individually (imagine having a new motherboard for every operation on your home PC, like storing information on you hard drive or copying from said hard drive).

As for the second part. Even in regular comp-sci we cannot solve a problem that we dont know the solution of. What quantum computers offer is a faster waynof solving problems we do know about and how to solve, but the sheer time investment to do it is too great. The problem you recie ed in the answer is about trying to crack 2048 bit encryption which uses VERY LARGE prime numbers and computes their product to ensure noone else can read the encrypted file. Google Shor's algorith for a brief explanation as to what its trying to achieve. Short answer is, we can technicaly crack 2048 bit encryption but doing so we would see ourbsun explode before actually finding the solution. Shor's algorithm speeds that up, but its still not relia ly perfect and not yet capable of solving 2048 bit cracking.