It would do nothing to those people with fast internet but would help alot with people who live in third world countries with crappy internet like mine
Also because other sites like chess.com and ICC have it up to 2 seconds, it's only fair that lichess should have the same rule too
Besides, it's "up to"
Pretty sure this small change won't make games magically last absurdly long since it seems that many people here have decent internet
Thanks in advanced