Based on what I've seen: They essentially "shut down the Internet" for probably a quarter of the global population for about 3-4 hours.

That response time is atrocious. It wasn't that they needed to fix broken hardware, rather they needed to stop running hardware from actively sabotaging the global routing via the inherently insecure BGP protocol. That took 3-4 hours to happen.

As an example: Being in Sweden with an ISP that uses Telia Carrier for connectivity things started working around the time of https://twitter.com/TeliaCarrier/status/1300074378378518528