This seems like Google's version of Vercel, Netlify, AWS Amplify, Cloudflare Pages, etc. But especially Vercel, since they've expanded past basic Node hosting and integrated serverless workers, KV, Postgres, etc. – positioning them to be able to take on Firebase for some use cases.

I'm generally a fan of GCloud over AWS, but I don't see any advantage of this over Vercel. Vercel is way easier to use (as a dev) than anything I've seen in GCloud or Firebase. And them being behind Next.js means it's hard to find a better fit and feature parity (such as for automatic image optimizations) in other hosts... there's vendor lock-in, definitely, but with a much lower risk of overnight sunsetting.

This is a side project for Google that will probably disappear if/when it fails to pick up enough steam. For Vercel, this is their main line of business. Why should anyone choose Firebase?