First of all, Stadia streams from Edge nodes - it's not about living next to data centers. I'm just giving another data point. There are numerous places for latency to be introduced in game streaming: encoding, decoding, local network, WAN, etc. An extra 15 seconds on your ping is a HUGE deal for playability in game streaming. 20 ms might be an awesome ping for CS:GO, but for something like Stadia you're going to feel that negatively.