Why do my sims just not do the tasks i give them?

avapannava​ It has been like this for ages. I can't see them doing anything about it, it's a subject always appearing in the forums. At one point they said they fixed it but it isn't fixed. It is very frustrating sometimes. The worst one is when you are trying to feed the infant in the highchair and another sim comes and takes them out of the chair, then all the other sims come wanting to check the infant so they just end up all stood there doing nothing.