Earlier quoted context omitted.
Speaking as someone who has graduated over a dozen PhD students in computer science... Yes, it is possible to complete a PhD in 3-4 years, but it's not really good for your career. The bar our department sets for a PhD is that at the end of it, you should be a world expert in your specific topic. A PhD is more like an apprenticeship, where you develop and refine your skills, your background knowledge in your area of…
Taking a longer time to graduate to become the “world expert” in their field is fine if grad students weren’t paid next to nothing for the 60+ hours a week that they are expected to work. As it is now it’s better to finish as quickly as possible so they can have a real life.
Don’t want to deal with the machinations required? Opt for the masters track or just get an Undergraduate degree and spend 20y working your way up.