Season 6 Major Lag Every Match on PC

Yeah, but it's not lag, it's packet loss.

Lag is latency; the time it takes for data to get from one place to another. Laggy players (known as HPB's, or High Ping B***) often are far away from the server, meaning data takes more time to get to them.

Packet Loss means that packets are missing. Game data uses TCP protocol, which requires that all packets be accounted for. When packets are missing, the receiving end instructs the sender to re-send the lost packets. You end up rubberbanding everywhere because your position information is only updated once the missing data gets resent after the fact.

In short, the servers are dying, and the build seemingly has some kind of massive issue with it that's causing server-side instability across platforms. A lack of, or poor, QA process is probably at fault here. Chances are stakeholders held the dev team to unrealistic timelines so they just pushed out what they could, and skipped a lot of testing, resulting in these live-environment issues.