Technically, an external GPU could go a long way toward improving gaming performance by letting it use a desktop graphics card in a dock or enclosure powered by a PSU. Some newer laptops offer Thunderbolt connections that can properly connect to one, and many others can connect to an internal mPCIe plug, though that's a more involved process and is something of a "hack". So I wouldn't say that upgrading a laptop for gaming is "impossible".
Things like CPU and RAM speed will limit performance, but I suspect that most laptop processors from the last few years should be able to manage 30+ FPS in most newer games if given access to a proper graphics card. Drive performance shouldn't make much difference for most games either, aside from increasing load times, and the storage device could always be updated to an SSD, if needed.
Not all laptops will be able to connect to an eGPU though, and of course, such a solution will not be easily portable. It's certainly not something for everyone, but it's a possibility that's there.
Of course, we don't even know what kind of hardware this laptop has, or what games you are trying to play. Maybe it's just a matter of having to turn down settings, reduce resolution, or make sure that the laptop is utilizing a built-in graphics card, if it has one.