How many companies at the size of Anthropic can serve the amount of traffic and manage the amount of compute they have?

It doesn't matter. Front end code should not misbehave if servers can't keep up. At worst it should fail gracefully.

How many compagnies can manage a mostly stateless workload at "whatever-the-scale-because-it-does-not-matter-because-stateless" ? Lots of people can do that. Massive amount of people can do that.

HN users are world champions are trivializing difficult things with snarky comments

I mean, it's Anthropic‘s front end, Michael. What could it cost? 10 dollars?

I mean, supposedly software engineering is solved so it's somewhat justified snark.