Is joining a voluntary pension scheme at a software company in England, without knowing where its money is invested, better than not joining, or is it better to know the places where the money is invested, so that if they are permissible, one joins?

Voluntary insurance involves two prohibitions: gambling and Maysir (games of chance), because the participant may receive more or less money than what they paid. The second is the investment of funds in usury or prohibited activities, which is usually the case. Even if we assume a lawful investment, the first prohibition still stands. As for compulsory insurance, the person obligated to it is excused, and many scholars have permitted benefiting from what comes from it, considering the surplus as a form of state care.