Market dominance based on market cap is an overrated thing. When bitcoin dominance was about 52% a lot of people were worried about how it was losing its dominance, and I find it very amusing because it's not important at all. When bitcoin had a market dominance of 80%, it wasn't this big. Ethereum has a market dominance of 11% but it's still one of the least performing coins in the market. A lot of the top coins by market cap are a fluke. Most of them have a ridiculously large amount of coins in circulation. If a coin like Shiba Inu, for example, gets to $1 per coin (I know it's almost impossible because of how shit it is), that will make its market cap around $589 trillion, which will mean it has a higher market cap than bitcoin. Does that make it more dominant?
According to CoinMarketCap, there are about 19 million coins and tokens out there, and hundreds are being created per day, so it's normal that the percentage of dominance by market cap will keep shifting. At the rate coins get created, I won’t be surprised to see bitcoin "dominance" go lower than 50%. It's very normal because people will use altcoins to get quick money, and that is why these coins always dump because people sell off to get profit at every chance they get.
When talking about dominance, we should look at how acceptable the coin is. Which coin is more acceptable as a means of payment?
Also, the popularity of the coin. Even though only a few percentage of the world holds bitcoin, a lot more percentage of the world know about bitcoin. They may not understand what it is, but they know bitcoin more than any other altcoin. There is no way you will know crypto and not know bitcoin, but you can know bitcoin and not know other altcoins, that's dominance.
We can even look at the coin with superior features. There's a reason big corporations choose bitcoin as their asset, and rumours of countries talking about bitcoin reserves. That's dominance.
The popularity of Bitcoin is surely on the high. Likened to the spread of wild fire!