Gold has had at least three millennia to establish itself as a store of value people turn to when social systems are in stress. Bitcoin has only existed for 11 years. While plenty of investors are willing to speculate on the possibility bitcoin might supplant or compete with gold, the idea is far from ingrained across society. When will it be more widely accepted? Perhaps when the international crisis of global leadership unleashed by COVID-19 undermines the capacity of institutions like the Federal Reserve to sustain economic and social confidence. Whatever new institutions and systems we create going forward will need to address how the internet has upended society’s centralized systems of governance. When that happens, we’ll need a decentralized, digital reserve asset as the base value layer. As I said, it will take time. Meanwhile, the developers will keep building.
Ethereum is another use-case for a blockchain that supports the Bitcoin network, and theoretically should not really compete with Bitcoin. However, the popularity of ether has pushed it into competition with all cryptocurrencies, especially from the perspective of traders. For most of its history since the mid-2015 launch, ether has been close behind bitcoin on rankings of the top cryptocurrencies by market cap. That being said, it's important to keep in mind that the ether ecosystem is much smaller than bitcoin's: as of January 2020, ether's market cap was just under $16 billion, while bitcoin's is nearly 10 times that at more than $147 billion.