As an organization, we use Team Drives in Google to manage it all and make sure everyone has access to all the files they need and we're not relying on someone to remember to share something with someone.
Files in team drives don't appear to be attachable in Aha. Read the other note about adding files/folders into My Drive, however Team Drives don't have that option.
https://big.ideas.aha.io/ideas/APP-I-5229
Sort of a duplicate of APP-I-5229. Nonetheless, it is a critical limitation.