There have been more than 19400 cryptocurrencies but strangely no one has come with an idea to restart bitcoin so to allow new users to buy and mine it from the start. We already know that 4 million or more have been lost. What stops a computer programmer to copy the entire bitcoin code and change only the limit from 21million to 20 million.
As others have stated, most of the 19400 cryptos you wasted are a complete waste of time.
Another reason that has been mentioned, is, why bother? There is nothing new to solve that needs urgent addressing. If the bitcoin community needed to change something urgent, and it was a breaking change, then a hard fork would merely be made, and the old version would cease to be in use just like that - so long as a majority is reached bu that's not the topic here.
Drastic solutions are only required for drastic problems, and in the current state of affairs, you will find little that needs to be solved in cryptocurrencies already.
[examples: smart contracts (ethereum), anonymity (monero), scalability of tx speed (tron), etc...]