This is not clear. The article is talking about traditional seeds for which that could be true (I don't know what is traditional in Kenya). Other commenters are talking about Maize which is from America and thus not traditional in Africa and thus there are no traditional seeds in Kenya. Maize also benefits greatly from hybridization, but there are other plants that do not, if we are talking about Maize you are wrong new seeds are much better than traditional, but if we are talking about other seeds who knows.

See e.g. https://apnews.com/article/kenya-seed-bank-agriculture-clima... , which is linked from TFA.