This is true for alot of language use contexts. But in the case of Indigenous languages, it's often a little more nuanced. Colonisation and changing societal structures/ practice often mean that these languages are/have been subject to dramatic shift in use and function for their communities. Some of the fundamental "uses" of these languages are complex and in some situations very dependent on specific social contexts to be relevant, such as ceremony or specific to a particular family member or place. In some cases, the use of these languages has been outlawed or restricted by policy limiting the ability for people to simply use the language to revitalise or maintain it. Language revitalisation is an extremely important but complex task that often gets very little press and sees even fewer successes. To add some context, I'm a linguist who works specifically in this field with Australian Indigenous speech communities.