Let me chime in here. Think of crypto as a new design of the internet itself. Each “neo-internet app" that has weight will sink to its best use case. The foundational deepest layer is the neo-internet reserve asset — that’s Bitcoin. There won’t be another Bitcoin because no one needs another Bitcoin and thus developers won’t want to waste their time maintaining another Bitcoin. In the legacy financial system there is only one base central bank reserve and that is gold. Diamonds, silver, uranium, etc are also very valuable per ounce, but the world only needs and recognizes one base reserve.
Alt coins are other neo-internet apps that serve different purposes than Bitcoin and a process is playing out now to see how much weight each has and to what layer it will sink. (By now you should have figured out that I am calling blockchain technology the neo-internet.)
As thing stand now, 96% of alt coins actually actually run off the Ethereum platform. For example, I hold physical gold on the neo-internet through an altcoin called KAU which sits on a popular Ethereum standard called ECS-20. Ethereum provides the contractual trust needed for me to be certain that the KAU I own is truly allocated to me and stored in a specific physical vault. If Ethereum truly becomes the general backbone of the neo-internet, then one ETH could someday be worth more than a Bitcoin in the same way that all the stock of the current companies that make up the infrastructure of the current internet have a combined market value higher than gold.
There are altcoins striving to be a layer that facilitates faster exchanges of value (xrp is in that category). Central Bank Digital Currency will, among other purposes also seek to provide more efficient exchanges of value. There are altcoins striving to do what Ethereum does, but better. There are altcoins designed to structure a new system of banking and financial services (called defi in general).
Besides Ethereum, the only altcoin I invest in is Chainlink. It is specifically designed to be the best interface between the neo-internet and Oracle databases running on the legacy internet. I also invest in a bank holding company on the NYSE, Silvergate, that specializes in providing a 24/7 interface between neo-internet apps and the traditional banking system. This year Silvergate actually out-performed Bitcoin. There have been times in the past when Ethereum and Chainlink and other altcoins outperformed Bitcoin, and that will likely be true againin the future. But…
…there is only one Bitcoin.