I have 10Gbit and hunted that whale. But I didn't build my own router. Electricity is $0.51 Kw/h. Ouch.
First, 10Gbit hardware is more available now than years ago, so you have more options. I started off with the router my ISP gave me. It worked, but it was 1Gbit. Not going to do for me. Plus, basic function was paywalled. Booooo! Snagged a broken Asus router and got it working great.
With IDS/IPS enabled, I get about 3.5Gbps. There is newer router tech today that looks interesting with fewer bottlenecks that would have been nice years ago, but not worth the upgrade right now.
My desktop hits about 2Gbps downloading Steam games/updates, but my partners desktop lags behind with SATA SSD storage. Definitely need NVME with that speed.
I will say my experience with 10Gbit Ethernet cards is not positive. I have a lot of intermittent disconnections and there are a lot of bugs vs 1Gbit switches. They do not like sharing with 2.5Gbit devices. I keep my server on 1Gbit connections. It's plenty fast for my needs though.
Edit edit: perhaps my comment was irrelevant. OP is specifying Google Cloud specifically.