Have you seen popular games on launch day falling down on auth flows? That's largely just HTTPS text connections via REST. Now add in a binary data stream on top of that (likely RPC, but I'm not sure of Twitter's implementation).
All that said, Twitter dropped the ball due to Musk's arrogance. Instead of having limited issues, it was riddled with issues as a result of him firing all the people that could have reduced the issues. As was foretold by our ancestors.
~200,000 simultaneous connections vs ~2,000,000 simultaneous connections is a world of difference.
Additionally, while a successful Zoom call, it still had issues, with a dedicated Zoom support team.
Nothing about either of these events were "easy" or "fine".
The big difference is that Musk is an arrogant idiot and decided to roll-his-own streaming service with a reduced headcount and a product that that is lacking proper load balancing, reservations, & scaling through load testing & real world tests scenarios that ramp up scale over time.