I agree that there's benefit in hiring a broker when selling.

But I'm not as convinced that brokers are necessary when buying; at least to me, it seems like selling a house will often be more work than buying one. When selling, you need to advertise the house, show prospective buyers around, research the market to better understand pricing, etc whereas for buying it seems less time intensive overall, and easier to find some reasonable options, meet with sellers or listing brokers directly, and write a persuasive offer letter.

I recently bought a condo in NYC without a broker, and if you're interested, I left a comment with more info about my experience: https://news.ycombinator.com/item?id=18927393