There's a difference between doing the minimum to unlock content and picking up tons of one-time treasures. That's what this thread is about-- skipping all the treasures and as many quests as possible when you level up, then delaying as long as possible even at maximum level.
The fix is very simple; one-time artifact power gains should not be affected by artifact knowledge at all.
One-time artifact power gains added in later patches should simply be much larger, at baseline. They shouldn't be affected by artifact knowledge either.