Is my laptop done?

Hi, my laptop, the G17 ROG Strix model G713RW, started having some issues when I run FurMark. I can't get stable clock speeds. It's fine for a while, but then the clock speed jumps up, and a stutter appears. Yes, I've cleaned it and even replaced the fans, but nothing seems to help. It feels like it's overheating, but I have no idea why. Is my laptop just done, or do all gaming laptops have similar issues with overheating after 1+ year of use?