Technically, no. But, I have yet to see an opportunity that couldn't have been made better by using a buyer's representative. Terms, conditions and price.
Often, first-time buyers don't know differently and embark on their home hunt by looking at random homes by calling every agent that has a listing on a particular street. And they call all the private sellers too. This would be like them contacting the coach of the opposing football team for advice -- you wouldn't do that would you?
A better use of their time is to find an agent that they get to know and trust and then use them to set up convenient appointments all at one time. That single agent can also compare and contrast the homes (which had they called all the listings agents, they would likely skew all the comments in favour of their own listing or more likely omitted the ones that weren't favourable. Obviously, if they called seller then they couldn't get any factual information on the other homes available).