BG3 is single player offline game, mainly distributed globally through Steam (and GOG) which runs it's own CDN for games. There is a multiplayer mode but that is co-ordinated via p2p for the most part.
The "IT team" at Larian doesn't get hit with those downloads as they only send a single copy up to Steam's CDN which handles the traffic (perhaps some backend user authentication too?)
so essentially this article is "Baldur's Gate 3, is a very popular download on Steam" just buzz to push more sales presumably.
700k players when you:
- Don't run your own game update distribution/patcher
- Don't provide real-time chat
- Don't run your own arbitration (what's the point if mostly everything is P2P/high trust sessions and cooperative?)
- ...
700k players is great for them and by all accounts they seem to have done a great job overall, but it's a far cry from League of Legends or even DotA2 in terms of system stress.
It's worse than that, it's creepy. What is a single-player offline game phoning home anyway? On every play? It's crazy how much software companies get away with these days.
The frog is well and truly boiled.