When encryption fails

I've been studying encryption for a long time, but have also done a lot of code-breaking through frequency analyses and just simply running it by the computer, but all the same.

I've gone over a dozen different puzzles that involved this, and the result usually that I solved it but does this mean that encryption is failing?

I think it depends on the encryption, but most of the time people can figure it out if they're good at it, or they had some help? But nowadays people are also using AI to solve encryption, and soon enough quantum computers will crack any known digital code!