Fidelity Digital Assets released a report on why Bitcoin is fundamentally different from other digital assets. Here is the Full Report (PDF download from Fidelity).
Quotes from the Report:
Bitcoin’s first technological breakthrough was not as a superior payment technology, but as a superior form of money. As a monetary good, bitcoin is unique. Therefore, not only do we believe that investors should consider bitcoin first to understand digital assets, but that bitcoin should be considered first and separate from all other digital assets that have followed it.
Also:
Bitcoin is fundamentally different from any other digital asset. No other digital asset is likely to improve upon bitcoin as a monetary good because bitcoin is the most (relative to other digital assets) secure, decentralized, sound digital money and any “improvement” will potentially face trade-offs.