The convenience of security
Collateral has advantages in being simple, minimalist, convenient and some are even provided free of charge. Many tenants tend to provide collateral to landlords, and then regret it.
For example, a young couple rents an apartment and their parents sign a letter of guarantee that the young couple will not violate the provisions of the tenancy agreement.
In case of a dispute between the tenants and the landlord very quickly the guarantors will sometimes have to be dragged to court because of it.