And looking at this fundamental value, other cryptocurrencies have arguable superceded it in terms of better tech/efficiency, so the value seems incredibly hard to justify.
Look into DASH, it has a fundamentally different architecture than bitcoin. The biggest pros are instantSend, privateSend, and the DAO (A governance system).
In addition to the other response, another example is ethereum's ability to offer smart contracts, which is not possible with bitcoin. Transaction rate limits and power consumption also are more efficiently handled.
They're different, which is why I used the term arguable--there's no clear reason afaik that bitcoin should be so valued relative to others, but I could be wrong.