remember that boto3 was released separately - https://github.com/boto/boto3

Does boto3 becoming 1.0 last week mean that everyone should be moving to it or will boto3 merge into boto?

There's also libcloud, which is a unified API https://libcloud.apache.org/

Some AWS specific functions, particularly for newer products or options, aren't always there immediately so you end up having to use boto in those cases. You also sometimes use provider specific options on functions, so it's not totally write-once and ignore.

Great point :-)!