When me and my friends are playing or afking somewhere and villagers or even animals that we have interaction with just disappear, and can be very annoying at times, like for an example we like to trade with villagers but random one will go missing and they have name tags and they should despawn either. And it that same with animal we would be use them and stop using them for a while and they will all just disappear and it's very annoying depending on what they are used for and same goes with the mine cart.