I think that only 10% coins/tokens that would be able to survive and will be worth investing in 2021.
There are currently 2400 tokens that are known and many unknown to anyone. By the end of the year 2020, at least 100-200 new tokens will be created. Every day in the world there are 5 new airdrops. I think it is not realistic to calculate. But I'm pretty sure new tokens are being created more than they are being deleted.
But we have to buy only good market capitalization coins. Don't invest money in shit coins.
Im not sure if a token which already created can be deleted, since the smart contract already deployed on the Blockchain and cant be reversed anymore...
So its will available as long the blockchain live. Im agree that we need to be more picky to invest since theres's too many option to invest,
also i prefer to invest to coin instead token since the development is more serious than just a token...