Its a matter of your own analysis whether you do trust the project or coin you been holding for long term or not because there are really instances on which we do really mind off on selling it once we do
see some opportunity for us to do so and there are instances on which we dont care nor skip out just because we are really that aiming for long term which is something depends on someones particular goals.Yes, we dont need to hold for all of our life but it would really be basing on someones particular goals or targets which would really vary to each other.
It is a bit also about the project and the popularity and the sanity of it as well. Like if you buy bitcoin and hold it for veeeery long time, I mean like decades, then nobody would question that, same could be said about ETH and BNB as well probably. However, if you come out and say that you will hold Shiba for a decade, then you will raise some eyebrows. So yes, a bit of your own analysis and researching the project matters, sometimes you just have to go against the publics opinion, but at the same time there are also a few coins that would be accepted to hold long term by everyone, so it doesn't require you individually making sure of it being good, because everyone accepts it as a good one.