For comparison, bandwidth that costs me if I directly peer or rent from a European hoster 20$ a month costs at GCP over 900$ a month. With Firebase, it'd be a major 5-digit sum even.
Seconded, for similar reasons. Even in the US, for $400/mo you can get a colo with an unmetered gigabit pipe (Hurricane Electric, FDCServers). Assuming you only use it 50%, that's about 160TB, for a final price of $0.0025/GB. Google internet egress is 32x more expensive and that's with the steepest discount. Hell, even their CDN interconnect pricing of $0.04/GB is 16x more expensive than standard egress pricing.
In Europe their pricing is even less competitive.
It's insane how much they charge for bandwidth and it severely limits the usefulness of the service.
I guess that might be the point though. If egress is expensive, you're encouraged to keep everything inside GCP.
N.B.: My use case is batch jobs that have a significant amount of output bytes, so I don't care about the "quality" of the bandwidth.
And for those who aren't aware, Google is charging about two orders of magnitude more than market rates for Internet egress.