But seriously, imagine you and I are both bidding $1,000,000 on a house. You have an agent, so if your bid is accepted, your agent and the sellers agent each get $30,000.
I don't have an agent. In my offer, I write "the sellers agent gets the usual 3%, and I am allocating the 3% that the buyer's agent would get towards the seller instead." That means for the seller's agent there's no difference whether I use an agent or not, but to the seller themselves, my offer looks $30,000 better than yours because I am sweetening the deal using that $ I'd otherwise give my realtor.
All that said, I used a realtor on my house purchase despite being financially savvy and a good negotiator because they actually helped us find the right house, and they were well worth the fee.