Which word describes someone excessively eager to provide unwanted services or advice?

The term that best describes someone who is excessively eager to provide unwanted services or advice is "officious." This word is often used to refer to individuals who take it upon themselves to offer help or guidance, even when it is not asked for or needed. An officious person may come across as meddlesome or intrusive, as they tend to overstep boundaries in their desire to assist others.

In contrast, obfuscate refers to making something unclear or difficult to understand, which does not align with the behavior described in the question. Mitigate means to lessen the severity or impact of something, while obtuse typically describes someone who is slow to understand or perceive something. Neither of these terms captures the essence of someone who imposes their unsolicited help on others. Therefore, "officious" is the most accurate choice for describing such behavior.