Most altcoin buyers don't even want to install the coin's wallet, usually they just keep it on an exchange. That tells you all you need to know about how "important" that coin is.
If you like facts, check here market cup of Bitcoins and altcoins - https://coinmarketcap.com/.
Bitcoin - $488,641,112,069, and first TOP10 altcoins - ETH - $185,507,720,235, Tether USDT - $82,980,995,714, BNB - $31,595,128,368, USD Coin - $26,087,042,560, XRP - $24,977,298,271, Dogecoin - $8,453,108,756, Cardano - $8,453,108,756, Solana - $7,247,799,860, TRON - $7,247,799,860 with total market cup ~ $382,000,000,000.
Or something different - the total crypto market capitalization is currently $ 1.02T, Bitcoin market cap is $ 488.92B. BTC currently has a market dominance of 48.19% - so altcoin market currently win - https://coincodex.com/market-overview/