As far as I am concerned, we really only need around 2-3 cryptocurrencies of the following five types;
1. Pure cryptocurrencies, e.g. Bitcoin, Litecoin and BCH
2. Stablecoins, e.g. Tether, Circle and Libra
3. Smart contract coins, e.g. ETH, TRON and EOS
4. Privacy coins, e.g. Monero, BTCP and ZEC
5. Corporate liquidity tokens, e.g. Ripple and Stellar.
Overall, that means there should be around 15 cryptocurrencies. Can anybody convince me otherwise?
Very difficult to put it any better than this. We can expand this list a bit and add another 5 categories to take the total number of categories to 10. 3 cryptos per category would mean a total of 30 different coins. And right now we have more than 10,000. IMO, sooner or later, we'll be witnessing a major consolidation in the altcoin market and many of the smaller coins are going to vanish.