I think @jammycakes explained this pretty well, but to boil it down, as best I understand it: Mutations are random, as best we can discern, but which mutations survive is not random, because the environment naturally tends to favor certain sorts of things and not others.
The recently posted video about antibiotic resistance illustrates this beautifully. You have millions and millions of microbes. If you have even one that develops the ability to survive in the antibacterial environment, it will not just survive but massively reproduce. 99%+ of the microbes might die off when they hit the antibacterial substance, but the one that survives will conquer the new environment, and that’s all it takes.
This means that the overall pattern that emerges over time will be one of life adapting amazingly well to new environments. This overall pattern is not random! But it uses a random algorithm to get there. Does that make sense?