You have to just stay in their ecosystem and you’re forced to use their tooling, and their stupid decisions.
To use Go as an example, Google wants Go developers to use boringcrypto. 2 years ago, a Red Hat developer added OpenSSL support to boringcrypto and submitted a CR, which was outright ignored. Months later, Google explained that they’re ignoring it because “I don’t think OpenSSL support is on our roadmap for boringcrypto”. Google wants so badly for boringcrypto to not support OpenSSL that they ignore code reviews, even when multiple people followed up afterwards saying that they really wanted OpenSSL support to be added.
That’s not open source, it’s just writing proprietary software where other people can see it.