Yah true to some extent. In summer we lose a couple percent per week if the car goes to sleep. In winter that’s more like 1 percent per day.
I have also seen a 3 to 5 percent drop overnight when parked outside at minus 27, but that actually comes back as the battery heats up. Eg, if you drive it into a warm garage it will actually come back. But that’s different than the vampire drain you are talking about where the power is actually consumed by various vampire loads.
if you want to see a tesla go thru power fast just sitting there just leave sentry mode active. That means that every camera is active and recording. The car will suck up 8 percent per day. We have done that before in hotel parking lots etc, or somewhere where security is a concern. We use it, but not often.
Hope that helps.