Are viruses still an issue?

The reason viruses are still an issue is because PCs allow most programs to have access to your source folders, the ones really deep in your C drive that hold all the code for your computer. There's one folder in there that is the "startup" folder, and certain sites and programs could save an extra code into that folder (or another one that opens automatically) and when your computer goes to that folder to get what it needs (the startup folder has everything it needs when it starts up) it'll open up the malicious code aswell, which can literally control the computer.