How many requests does IG handle per second? I am not even going to guess a number but I am sure 1000 specific requests would drown in that. So you would need a dashboard that specifically visualizes this kind of thing. Do that and you are now protecting yourself in one type of scenario. But there are endless other scenarios that you still wouldn't see.
I'm sure IG gets several orders of magnitude more than 1000s of requests per second. Even if a dashboard existed visualizing excess request traffic per route per user, when you're talking about this kind of request volume, there is an indexing lag + a reporting lag + alerting lag (assuming there is alerting on this specific scenario on top of the dashboard) + human or automated response lag. It sounds like this attack could be completed in minutes rather than hours or days, it's feasible that it would have succeeded well before anyone got around to mitigating it.
But once you know that this is a specific attack surface, it's far easier to limit the surface (fix the problem) rather than build a dashboard that a human has to monitor perpetually.
