If Google’s own premium speedy network, anycast IP, global load balancing and security features bring no benefit to your web operations, then your math might be right.
If you need your LB to handle 10s of millions of HTTP/S requests per minute, then what other choices do you have other than Google?
F/W default “Everything within a project should allowed”? Sorry, but no way.
Not familiar with other DO capabilities, but cloud platform is not just about a VPS available throu REST API, it is way far beyond.