No, romantic relationships between humans are not considered incestuous even though humans share about 99% of their DNA with each other. The term "incest" refers to sexual relationships or marriages between individuals who are closely related by blood, such as siblings or parents and their children. The genetic similarity between humans does not make romantic relationships between unrelated individuals incestuous.
The 99% DNA similarity refers to the fact that all humans share a common ancestry, and it is a characteristic of our species. It does not mean that humans are so closely related that forming romantic relationships with each other would be considered incestuous.
Romantic relationships are based on emotional connections, shared interests, mutual respect, and attraction between consenting adults. They are a natural and healthy part of human social behavior, and they occur between unrelated individuals who meet and develop feelings for one another.
In contrast, incest is considered taboo in most societies due to the potential genetic risks associated with close relatives having children together. Such relationships are prohibited to avoid genetic disorders that may result from the combination of similar genetic traits inherited from common ancestors.
It is essential to distinguish between the concept of shared DNA among humans, which is a result of our common evolution, and the social and cultural norms that define appropriate and consensual romantic relationships between unrelated individuals.