Whether CPU or GPU, as long as under 80c it's all good.
81c to 90c range - still fine but it's time to look at doing some cleaning / airflow improvement.
High-end graphics card rarely go over 75c these days, the fan will go with high RPM to keep things low. Cards like those using stock / reference cooler (eg Nvidia whatever model Founder's Edition) then the card reaching 80c is normal.
Temperature when playing AAA games