Here's a practical D2C exercise:
Take your last release. Answer these:
1. How many people bought it directly (not streamed)?
2. Can you name them?
3. Can you email them?
4. Do you know what else they've bought from you?
5. Could you offer them something new right now?
If you got through 1-3, you have a foundation.
If you got through all 5, you have a D2C business.
Most artists stall at question 1.