The obvious answer to the title, based off my understanding, is to be used as a currency. Obviously it’s not the most widely accepted currency right now, but my understanding is that all coins serve that purpose
My coworker mentioned his investments on crypto and said some things that confused me and clashed with my understanding. He said Ethereum is a company (with a CEO) and you buy the company when you buy the crypto (like with stocks). He also said when you buy ETH it’s like an ETF because other coins are built on that blockchain. I asked if he meant that as “They use the same blockchain model, or variations of that model” and he said no; they literally share blockchains with other coins.
He also mentioned being really into game-crypto; Like crypto from a game company? Is it mostly used for microtransactions? He also talked about a coin called DOT (I think) that’s like build to handle the logistics chain. It’s nonsense