It is not the same situation. If you write/read video sequentially, you get speeds about tens of Mb/s, and with swapping you get random access with speeds < 1M

It is not the same situation. If you write/read video sequentially, you get speeds about tens of Mb/s, and with swapping you get random access with speeds < 1Mb/s on HDD. So having limited memory buffer for video is better for the whole system.