Some tokens will stay tokens forever as they don't need to run in their own blockchain(hence they run on the ethereum network instead). Some cryptocurrencies though, like EOS, they're currently only a token as they're still at the 1-year ICO stage. After that 1 year, then they're going to convert to becoming a coin as they're going to need their own native blockchain.
So you mean that if the token is not running their own kind of blockchain it will never be a coin even if it is listed in top exchanges, has values, and got listed at coinmarketcap?. What are the requirements for it to be called as coins?
Coin = runs on it's own blockchain code, like Bitcoin/Ripple/Ethereum
Altcoin = runs on another blockchains codebase, I think most runs on Bitcoin
Token = lives on a blockchain, like ERC tokens on ETH's blockchain. Bitcoin doesn't (currently) support tokens, but for example Ethereum, Stellar, etc does
Tokens are easy to create and manage, since they live on the ETH blockchain for example, the ETH network keeps them alive.
If you made your own Altcoin based on Bitcoin's code as an example, you'd need a network of nodes, which means you'd need to find people willing to do this.
While a token, you just need to give value. Say you have a project in which your token will be used in some way, from there the value comes.
EOS as an example is a Token currently but they're releasing their own blockchain in june, and at that point a snapshot is taken on all EOS holders who can then convert them to the actual EOS blockchain.
However, for 99% of the tokens, this is not going to happen, and rightly so. Take Binance as an example, right? That's a token on ETH's blockchain. What purpose would there be for Binance-coin to run on it's own blockchain?
None, it's only purpose is to work internally on Binance for paying fees etc, and the value therefore comes from supply & demand to pay the fees on Binance, since it's the tokens only usage.
edit: actually I might be wrong about coin/altcoin, not entirely sure if altcoins simply refers to any coin that is on it's own blockchain and isn't Bitcoin!