Bitcoin was originally created to be a fiat currency that isn’t controlled by a central authority. Bitcoins value is set by all of the participants in its network and it has certain characteristics that can make it an attractive place to store value away from centrally controlled fiat currencies like the dollar.

Most centrally controlled currencies are setup to have at least mild inflation… the fact that your dollar will be able to purchase less in the future motivates many people to invest into businesses and assets that will grow in value over time (hopefully faster than inflation). At worst, governments can lose control of inflation, which can dramatically reduce a populations purchasing power in a short time, reducing their quality of life. A lot of people see the US and many other countries heading into a high inflationary era due to our huge deficits and debt. They see Bitcoin, which is configured to be deflationary, as a good place to keep their money in the long term bc the value will grow as the dollars value shrinks.

I see Etherium and many of the currencies based on it as more like tech stocks. They’re finding uses for blockchain technology that will eventually change how we do business so ownership in these currencies is basically betting on the next big tech company.

Then you have a bunch of meme/shit coins that basically have no use other than a means to speculate, like dogecoin. If you buy them, you’re just hoping it catches fire in the media so you can sell to the bigger fool later.