Not even the most dedicated gamer is going to burn the amount of electricity a miner does with the same hardware. That's not even considering the number of cards miners purchase...
The number of games that actually cause a modern GPU to hit its maximum TDP is also much lower than you'd think. If vsync is turned on, even a 3060 will trivially hit 60fps on older/simpler games, and modern ones unless the settings are turned way up. Games like Doom Eternal and Counter Strike Go are incredibly well optimized and can easily hit hundreds of frames per second on modern hardware. Likewise if it's a simple 2D game or more balanced title that leans on the CPU (unless you're using complex shader packs, popular games like Minecraft do a lot of their work on the CPU)
The number of games that actually cause a modern GPU to hit its maximum TDP is also much lower than you'd think. If vsync is turned on, even a 3060 will trivially hit 60fps on older/simpler games, and modern ones unless the settings are turned way up. Games like Doom Eternal and Counter Strike Go are incredibly well optimized and can easily hit hundreds of frames per second on modern hardware. Likewise if it's a simple 2D game or more balanced title that leans on the CPU (unless you're using complex shader packs, popular games like Minecraft do a lot of their work on the CPU)