What I'm not sure of is why Google published this. I can't figure out what their strategy is here. We never published about the attacks we absorbed because we didn't want them to know our capabilities.
Unless this is marketing for Google Cloud?
As for why to write about it, it's a new type of attack that resulted in almost an order of magnitude increase in attack size. That's interesting and newsworthy by itself, and publishing a concrete number gives people an idea of the size of the problem and the trendlines.
This is also something that needed a CVE, so it was going to be very public anyway. If nothing is written about it, at a minimum Cloud customers will be flooding their support reps with questions about whether the vulnerability applies to them.
Besides publicity, there is also link to a list of advisories that may be of interest to other cloud operators and users.
If you read the article, there are plenty of marketing remarks in there to get you to use Google Cloud
That seems likely here if they're claiming this is the largest DDOS ever.
We? Netflix or Reddit? I know for a fact that Amazon doesn't.
At eBay/PayPal we filed patents on our DDOS shield, since it was as far as we knew the first one to exist, but that was about the only public information on it.
At reddit and Netflix we didn't actually have to deal with it because AWS just absorbed (or mitigated) it before it ever hit us. We only had to deal with L7 attacks, which we had shields in place for.