Many coins in my personal wallet which already turned into shit coins because when management team swapped some coins into new one ,I didn't notice and all my old coins now valueless.
its your mistakes if didnt find and update about token swap from developers team. the first rule in crypto market when you hold some coins was always join in their chat group , there are important discussion about project developtment. Some project maybe swap their token , and holder must know about it. Usually they will give time line for is , and if you dont know till the end its really big mistakes.
yes, that is being a responsible holder. if you invest significantly on a particular coin, it is your choice how to manage such investment. and to secure your portfolio, you need to keep up with their updates before it is too late. it is not the dev's fault if they are giving announcements regarding the swap and the schedule, and yet, you missed it.
but the situation of having tokens or coins becoming worthless- i have seen that in my eth tokens before. didn't sell them because was hoping that they will be valuable in the market, turned out, only few of them made it and almost all of them went down the drain.
so right now, better invest in top alts with strong use case, that you know they can survive even after few years in the market.