Think of this in the context of what happens with the majority of other purchases you are making? How many of those have a "buyers agent" vs a sales person? I've bought houses in both the UK and the US, I preferred the UK approach where I found the houses myself (and in the US it's not that different with tools like Zillow etc.) and paid for a lawyer to handle the paper work for much less than the real estate commission that was paid (and part of the house price I ultimately paid).

In fact, you could really view the commission split paid to the buyers agent (from the seller) as part of that expense of the seller marketing their property.

if it were just an object, it makes more sense that the seller does the leg work. they know the object, the market, etc. they're the expert.

why does a buyer need a expert on all the objects out there?

I know there's technical examinations like a home inspection that the buyer would have done, but if you're just talking about navigating the property and legal docs, seems like the buyer isn't going to need an agent to do that other than once to accept the price.