I have the largest laptop GPU from the last generation; 3080Ti @ 16GB.

You must have very small fans moving a lot of air in a laptop. That means speed and speed is the primary cause of noise in fans. Larger desktop PC GPUs can have a larger heatmass sink and more/larger fans that run at a slower speed.

Aside from the noise, the laptop has a more complicated set of breakouts and interrupts for thermal and battery management. This means it may have different firmware/software support and issues if you do higher risk types of activities like messing with the clock rate.

One example I can give is when using AI on my laptop with various models I am able to split between CPU and GPU for inference. The thermal performance will impact throttling. I must balance both the workload and the thermals to maximize the inference speed for things like Low Rank Adaptors training where I need to run a model for a long time at near maximum output for my hardware. If there is more load on either, the shared thermal management will throttle sooner. Indeed I wrote a script to monitor the CPU/GPU temps and memory usage every few seconds just to dial in this issue.