Fifteen years is an eye blink in the grand scheme of things.
Let’s face it: Bitcoin is difficult to understand and aims to replace gold, at minimum.
Gold took probably a few thousand years to be understood and served as a good store of value for a few thousand years thereafter. We cannot expect Bitcoin to evolve so quickly. It will take time to embrace this paradigm shift.
I agree it's difficult to understand for the average person, while I fully support that it's still a new development. I also believe what @Lucius mentioned as well: a large number of people acknowledge Bitcoin, even though they don't fully understand it. Can it be compared to gold? They certainly have some similarities, but as Lucius mentioned, one is tangible and the other is digital, which is why the average person respects gold as an asset much more than Bitcoin.
Whether we like it or not, Bitcoin, cryptocurrencies, and blockchain technologies are complex matters that aren't for the average internet user. Expecting Bitcoin to be used for daily usage is "absurd" in a way that it's similar to transacting with gold. Bitcoin has become way too valuable to be used for something that I can pay with fiat or simply a stablecoin if I want to use crypto.