Bitcoin has dominates cryptocurrency market since 2009 and it has successfully maintained it for about one and a half decade. You can see Bitcoin dominance chart here
https://charts.bitbo.io/bitcoin-dominance/Look at the Bitcoin dominance chart with Bitcoin price, and you can easily see that Bitcoin mostly dominates the cryptocurrency market with its dominance is over 60%. There are limited months Bitcoin dominance lower than 60%.
Bitcoin is the pioneer that led the foundation of cryptocurrency market. All cryptocurrencies in circulation today are inspired by Bitcoin, so it's natural that Bitcoin will dominate the crypto market and rest of cryptocurrencies will follow it. No Alt till date is able to beat Bitcoin in terms of market cap and since the launch of Bitcoin ETF it look difficult that any cryptocurrency will surpass Bitcoin. These days investors are mostly inclined towards Bitcoin and paying not much attention to available Alts.