How can we have mass adoption if we're not trying to use it for payments.
The masses want to save and preserve their buying power. That's the most likely job Bitcoin ends up with in its present form if it becomes big enough and relatively stable enough. Hundreds of millions have exposure to stock markets. You can't use stocks for payments either.
Right, but the semantics of a stock are different and their intended use case is for buying power. Bitcoin was created with different fundamental semantics. If it's only exposure is to save and preserve buying power, there would be no need for it to exist. But of course, it's fundamentals are different.