Bitcoin market is I think the only crypto that dominates the market.Why? cause bitcoin don't die it multiplies (eg, .01 that has a value of $102 from one user and was sent to 3 users then were divided into 4, now we have four users that has .0025/each but since the market is still dominating the price might still remain at $102 for each of the 4 users.)
If we compare other altcoins against Bitcoin, we'll notice that the latter has much wider acceptance within the mainstream world. The reasons for this are obvious as Bitcoin is the world's largest cryptocurrency by market cap. Being the first original cryptocurrency in existence, it has managed to obtain a recognized branding that anyone trusts worldwide. Despite other altcoins being superior than Bitcoin in terms of transaction capacity with some additional functionalities, they're lacking the trust necessary to move on within the mainstream world. With lesser liquidity than Bitcoin and a lower degree of development, many people prefer to deal with the original cryptocurrency than anything else.
I believe that the current market situation is related to investors selling off their altcoins in exchange for Bitcoin. This brings up a greater level of demand for the pioneer cryptocurrency, allowing market dominance to rise like never before. Right now, dominance is rising faster than usual as people are losing interest into many altcoins being traded on the market today. Within a couple of years from now, Bitcoin would've obtained a market dominance of over 90% while altcoins become the minority. Even so, altcoins will continue to exist because they provide other features that are not available within the Bitcoin blockchain itself. With this diversity, people can choose from one crypto to another with ease. However, Bitcoin will be always be the reserve crypto of the market no matter what.
Nonetheless, Bitcoin's ever-rising market dominance shows us how powerful the cryptocurrency is within the mainstream world. Most altcoins will be seen as a gamble or a speculative instrument, while Bitcoin will be recognized by many as "digital gold". Which means that, Bitcoin will remain in its top position in market cap for a very long time. Just my thoughts