Is it permissible for the wife to throw away things—unsuitable ones—that the husband brought home from the street, which made the house resemble a landfill?

Your husband might have a legitimate reason for bringing these items, and if he does not agree to discard them, then you are not permitted to do so. If their presence harms you, then you have the right to demand that he move them or provide you with suitable accommodation. He should be advised to stop bringing useless items, out of concern for the cleanliness of the house. The relationship between spouses should be based on affection, mercy, understanding, overlooking minor faults, and considering each other's circumstances.