The altcoins do not have a great use in real life, if the altcoins had practical use in real life then the dominance of bitcoin would be much smaller and the falls of prices of bitcoin would not affect much the altcoins, but the reality is that the altcoins are focused on solving the problems of the internet, nothing against this, but there are already over 2000 altcoins and more than 80% of these altcoins have the same purpose
Actually some do have real life applications... Take an example of Ethereum. it has proved to be so useful for startups unlike bitcoin. Bitcoins only application is payments and maybe trading.
The only reason BTC is so dorminant is because it is the Godfather of cryptocurrencies.