@kempoutzzz I am comparing buyers agents to lawyers insofar as both can be included in a list called 'professional services', yes. You give them money, and they give you back time and/or take away risk, in comparison to doing yourself whatever it is they do.
Our buyers agent did three things for us that were valuable - noting all of this is in the context of two busy professionals who are happy to pay for the expertise of others where it can save time and/or reduce risk. For example, we pay someone to wash our second story outside windows (not that complex a task), to save the time and risk of doing it ourselves. As with any 'do it myself or pay someone to do it' decision, the calculus is a personal one based on resources (time and money) and risk appetite. And, as previously noted, choose a poor professional service provider, and any time/risk savings can flip into the negative. Your mileage may vary, buyer beware etc.
But yes, three things. First, they dug deep to help us make a determination on where to pitch an offer for a specific off-market property that we were in negotiations with, where neither party had a clear understanding of the value of the place, for reasons. Based on the guidance provided, we had confidence in our 'walk away' price, and were able to do with complete peace of mind (which is of course the same reason people buy insurance).
Second, they were our 'rapid response' eyes and ears for a very specific neighbourhood that we were determined to get in to within a short period of time, identifying a number of off-market properties for us, and giving us a good heads up on properties that were about to come on the market, in useful regular digests that we could work through each week, with a degree of confidence we were 'across the market' while also both working 60+ hour workweeks.
Third, when we found our dream property, they provided a valuable 'voice of reason' throughout the process. This includes having led what was a very heated/strategic auction process in a manner that we believe worked very much to our advantage.
Oh yes, fourth bonus thing - they also bid at auction for us at one property when the auction was the same as we had an out-of-town wedding to attend.