The "wealth" created is that there is a new house up for rent, and thus more options for those who want to rent.

The advantage of renting compared to buying is that you can occupy an house for a limited amount of time without being financially exposed to changes in the value of the house, without having to find a new buyer when you move out and without needing upfront capital or credit to buy it (there are of course also disadvantages to renting, so some prefer to buy instead).