The antonyms for the phrase "doth one thing" are varied, and depend on context. For instance, some antonyms for "doth one thing" in the sense of someone who is focused or single-minded in their actions might include "multi-tasking" or "diverse interests." In other cases, the opposite of "doth one thing" might be "procrastination" or "indecision," suggesting someone who is prone to putting off tasks or struggling to make choices. Ultimately, the antonyms for "doth one thing" will vary depending on the specific situation and meaning you are trying to convey.