There should be a gamemode for truer harder survival. With this there should also be some new features.
Inventory should be drastically reduced to only 2 slots (1 large or 2 medium items per slot, arms) when naked.
Also, there should be more slots for wearables (Belts for example)
Items to increase slots:
Pants (+1 slots for small items)
Belt with pouches (+2 slots for small items)
Basket (+3 slots for small items) Wicker basket, plastic basket, etc.
Cart (+1 slot for large items and +4 slots for small items) Wheelbarrow, shopping cart, etc.
Wagon (+4 slots for large items and +12 slots for small items)
Sickness and diseases should also be added. I will add more on disease later.