The relationship between Delta-8 and Delta-9 THC is complex, and it's important to understand how they interact with each other. Both Delta 8 and Delta 9 interact with the same endocannabinoid receptors, meaning that they can produce cross-tolerance. However, since Delta-8 is only half as powerful as Delta-9, people who use Delta-9 heavily may not experience much of the Delta-8's effects until they take a break and lower their tolerance. Cannabis and Delta 8 have very different tolerance windows.
The active ingredient in cannabis is Delta 9 THC, which is approximately twice as potent in its active effects. This translates into a more intoxicating experience and a much longer-lasting accumulation of tolerance. This Delta 9 molecule only binds to one set of receptors in the endocannabinoid system, the CB1 receptors. This means that these receptors contain all of the THC bonds, and that can cause a kind of deeper saturation, in which the accumulation persists long after the consumer has stopped using cannabis.