A good part of the Opuntia's in the trade, and even a considerable part of plants in habitat are hybrids. They normally combine the best of both parents, and often are hardier than either. Where they occur in nature, they can form swarms that can even surpress the parents. But the flower colours of hybrids are gorgeous, and through planned or unplanned hybridisation plants with desirable traits in flower colour, hardiness, growth form or plant colour or even fruit can be obtained.
The negative side of hybridisation is the selection of the plants that don't meet the expectation. That means disposing of unwanted plants. Also before getting the fruits of labour, it will take years of growing. Even plants that seem to meet the expectations can be disappointing (less flowers, sensitive to diseases). But the results can be spectacular.