But if an exchange goes through a hard period of time and shuts downs then ultimately that token will come to its end because there is no community other than that exchange supporting the token simply because it has no usage outside the exchange.
According to me exchanges should promote the usage of their coins/tokens outside the exchange to build a community in support of it. If your community consists of huge individual entities who believe you then a great community can be formed. Otherwise lack of applications would lead these things to disaster.
Indeed, there are now many exchanges launching their own coins. But some of them are only in individual exchanges, they don't release other exchanges. For example Hotbit with HTB. There is no double exchange. In contrast to Binance which has expanded. If Hotbit is not able to survive, of course, their coins are meaningless. But if the parent exchange is no longer active, even though their coins are listed in many exchanges, the coin will sink. That is, there will be no users. But I am sure, if the exchange goes well, even though the coins are only registered in an individual exchange, then this coin will have a high value. This will even make it easier for CEOs to control the price of coins.