Human-managed hybridization and selective breeding are by nature incremental modifications of living systems that have evolved their current form through billions of years of incremental evolution, tested by natural co-evolution and co-habitation uncountable numbers of times throughout those billions of years. The processes of modification used in hybridization/selective breeding mimic the well-tested change-processes of natural evolution.
In the near future, on the other hand, arbitrary genomes (assembled under computer program supervision from individual nucleobases) will be constructable with genetic engineering / synthetic biology science and technology.
The number of different possible living systems/subsystems/mechanisms thus constructable is literally, not figuratively, exponentially greater than the number that have already been incrementally designed/constructed by evolution or evolution+selective breeding.
Are you really trying to tell me that the risk level from that arbitrary synthetic biology is equivalent to the risk from selective breeding and hybridization?
Mathematically and logically, that is not a supportable position.
The risk level of synthetic biology (the unknown, perhaps unpredictable risks component) is a function of the number of possible novel mechanisms/subsystems/systems and the extent to which those novel mechanisms are different from pre-existent, evolution-tested mechanisms/subsystems/systems.
One can say, and tactically, one would say, that most arbitrarily human-designed and engineered synthetic biological mechanisms/subsystems/systems will obviously fail to thrive, but that is a red herring, because with enough cleverness, a proportion of them will thrive, and that proportion, still potentially an enormous variety and sometimes with substantive difference from existing living mechanisms, is what poses the risk.