My parents bought one of those when I was shorter than it. I visited them recently and it's still going strong three decades later. The wheels have been replaced once or twice and it's had other bits repaired, but with pretty minimal care it keeps on trucking!

PCs don't "generate" dust. Dust will accumulate inside/around them due to the high airflow they create though. All that means is it is dusty in your room/home. Dust is generated by your body (flaked skin, hair, body oils, clothing lint) and things you interact with (bedding, carpet, paper products, dirt from shoes, etc.)

You need to change your hygiene habits to reduce dust generation. Vacuum more often. Shower more and use skin moisturizers. Make sure to wash and change your clothes/bedding often.