1) If adoption rate can increase, then it is possible that bitcoin actually pass for Gold 2.0 because like you said, the more the demand of bitcoin, the more that it appreciate and this is also the case of gold too, so bitcoin can still be held as store of value right now, just like the way people do hold gold believing that its value will increase.
2) The adoption rate of bitcoin is still very low, and if at this level of adoption, the price has already crossed over $7000, now imagine what the value will be in future when we have high growth of adoption. I don't know the percentage of adoption right now, but I am sure that it is still not up to 10 percent off the whole population. The market cap of bitcoin will still enter trillions definitely as we have more demand, so to me, bitcoin is more like gold right now.
Is it really necessary to have an "adoption rate", do we really have to have statistics about that?
1) The changes in Bitcoin's price isn't the same case as the gold. If people mined "gold" it doesn't necessarily affect its charts in the market, as it has a very "stable" market price. Unlike Bitcoin, since it is being mined "constantly", we can already see how it affects the charts in the market. Scarcity is the key--recap: the less the quantity of a priced "object"(tangible/intangible), the more valuable it is--Gold's scarcity isn't determined because we don't actually know every piece of gold sitting on this Earth, on the other hand, we already have determined how many Bitcoins are there, though we can't determine how high its market price would go, but I'm pretty sure it will be more expensive than Gold ever was.
2) Bitcoin's price was $19k in 2017, though it's just a massive bubble, I could assume that the number of users(who owns, holds, trades) now isn't that much of a difference back then. Though exposure would help(?), it will still be determined on how much.