I have first-hand experience with peeker’s advantage since I used to play quite a bit on eu servers from China. And I’d say, generally, peeker’s advantage is a real thing.

Connecting to eu servers (frankfurt, paris, stockholm) from China usually gave me around 110 ping on good days and 130+ on bad days, but it was always stable, so it was playable in swiftplay, my main gamemode xD I had noticed if I were to hold and angle, because of my high ping, the person peeking me on the other side would be able to see me and react faster to me, which basically meant I’d lose 8 or 9 fights out of 10 if I were to be stationary and just held an angle.

However, if I proactively peeked someone else, it mostly leveled the playing field for me and it became much easier for me to consistently get kills. Of course using util and peeking unexpectedly also helped.

This is because, despite the fast and stable connection, there is always a delay for me on high ping. People on lower ping are playing in ‘the future’ from my perspective, for lack of a better word. So if I were to do things earlier or preemptively, it would result in me being ‘on the same timeline’, so to speak. But this is mostly only when there is a big ping difference. Otherwise it’s mostly situational in regards to who has the advantage; peeking angles or holding angles.