Well, it depends on the person who's doing that. Maybe keeping a token on their wallet already became their hobby instead of using it for trade. As for me sometimes I am hodling tokens depends on the usage of it or when I belive it will have good future. If not I prefer to buy and sell instead and taking profits from it.
It seems to me that the most used coins on the market are coins and tokens that are used for casino games. All other projects now holdings on users' wallets because they are waiting for the technological development of the market
token and coins have its own usage as long as ecosystem already formed. not always token used for casino games, its depend on token utility it self. if token already have usage in their ecosystem, automaticly its price will rise smothly, especially if used as gas. when there is transaction , token will automaticly burned. users holding token because they waiting the moment its token will have high value.