A broker is an intermediary: intermediaries exist in many fields, usually involving smaller amounts than in the real estate market.
But I actually do not know of any area where the consumer pays the commission. It is always the provider, whether it is the travel agency or the insurance broker.
But: this brokerage fee is included in the price everywhere. We just do not see it because it is comparatively small, so that the consumer does not notice it.
It is different in the real estate market, where lower volume but higher prices play a role.