I'm on a couple of pretty sizable discord servers with channels set up to discuss it. The vast majority of people in there haven't even been able to log on at all. I saw an estimated queue length of 11 hours thrown in there.
Back in the Stormblood launch window for FFXIV we had instance server crashes, and there was an instanced event right at the start of the expansion and in order to trickle as many people through as possible we had to resort to physical queuing, too. Because otherwise we were just flooding the already overcapped servers.
I had no idea the Twitch desktop app was the rebranded Curse client and still has mod support for this. Wish I'd known that from the start since there's a lot of handy levelling guid mods that help in the early game.