I never understand this. Why would a machine get painfully slow after a few years of use? Do you install rubbish on it? Do you not take care to ensure that ever

I never understand this. Why would a machine get painfully slow after a few years of use? Do you install rubbish on it? Do you not take care to ensure that everything in your process task list makes sense? Do you look to see what's gobbling up CPU, memory or startup time? I have had Windows machines for decades and never reach a state where the machine is slow or that it slows down since installation. The only thing to cause that is running endless taskbar apps or background services. What are you doing to make it slow?