Any reason Boto3 has not adopted Python truststore?

[byjrack]

Using awscli in an organization where proxy inspection happens. We try to advise folks to use AWS_CA_BUNDLE, but it's tough to educate thousands of folks about what to do and why. Is there a reason why boto3 has not pulled in truststore to help with CA trust? Still holding onto py2 compatibility? It made a huge difference in some other efforts where Requests was in use and reducing incident volume so it was worth the bigger supply chain. And yes its all documented, but doesn't get very far in reality. I just didn't know if I couldn't see a specific issue that was preventing using it as a path to zero-config CA trust in orgs where system CA trust is managed.

Figured before looking at a PR I would get a bit of a sanity check on if there was a blocker that would be non-trivial to get around.