Depending on the game, it can definitely eat a Mbps on average with spikes higher and lower, especially for competitive games with 64 or 128 refreshes per secon

Depending on the game, it can definitely eat a Mbps on average with spikes higher and lower, especially for competitive games with 64 or 128 refreshes per second (Or more with opportunistic updates). Recommended bandwidth for Counter Strike is 1.5Mbps, Overwatch is 3 Mbps. It's not much in comparison to watching 4K footages, but it's an order of magnitude higher than 30megabytes.