Torrenting at 500kb/s means the whole network is slow

Hey there forums, i am really confused on this. So another user on my network is torrenting a gigabyte file at a rate of 500kb/s, and we have 50mb/s internet. So when another user is torrenting, it seems like the internet is slowing down massivley, when i am playing video games, (LoL and MS) the ping skyrockets from around 20ping to 100ping, i have tested this enough to know that it is not a coincidence. Is there a reason that everything slows down when something is being torrented?

Torrents can be quite legal and I see nothing in the OP's post to state otherwise.

Legal or not has nothing to do with the OP question, after all.
I'll try to get to the point instead.

500 kb/s seems slow for a 50mb/s connection, but that may be easily explained by a poorly seeded torrent or peers with slower speeds (BitTorrent, contrary to almost everything else, works best with many people using it). Improper network configuration or port forwarding may also result in slower transfers that otherwise possible.

As for the slowdown of the general network, the only thing I think is a poor quality or defective router or switcher. As torrents normally create multitude of connections to multiple different targets, cheap home routers may be easily crashed by that. Try resetting it to test that, at least.

The router that is in my household is a PF Sense (https://www.pfsense.org/),