Correction or reduction?
Some would argue that in general, it is appropriate to prefer the correction of the non-compliance or defect over the alternative of reducing the rent.
But again, there may also be cases where the landlord will prefer financially that the tenant will reduce the rent than correct the non-conformity or defect.
Assume that towards the end of the rental period the central air conditioner broke down.
After all, the cost of repairing the air conditioner is tens of times higher than reducing the rent.
Or in the event that at the end of the rental period a defect was discovered in the sewer system of the apartment which requires the replacement of the entire sewer system in the house.