I know my laptop is not designed for games, but when I bought it I wasn't expecting so much headache. It's an i14 5480, and it time it reaches 68º celsius, the gpu power is decreased drastically. I already did an undervolt, but it's not enough.
Unfortunately even higher-end premium laptops like the XPS models thermally throttle these days. The new norm is to design systems that can run fast for short bursts of time, since for many users that benefits their use case. But sustained heavy load is an issue, and pretty much the only laptops that will handle that these days are the really chunky 15” systems like the Precision 7000 Series and the Alienware models. But your Inspiron 5480 doesn’t even have a discrete GPU, so gaming wouldn’t work very well anyway — although a dGPU would of course only increase the thermal load.