In my area of NY it's the same. We have very few buyer's agents.

Yes, here on Long Island Buyers' agents are few are far between. I have my CBR ( local version of ABR) and it is an uphill battle.

In Missouri, there are specific types of agency; but the starting point (and assumed role) when working with a buyer is Transaction Broker, in which neither the seller or the buyer is represented by the agent.

Any designation other than Transaction Broker requires signed agency agreement paperwork. The exception is when the property is listed with the selling agent's company (either by the agent or by another agent in the company). In that case, a selling agent can only be a seller's agent or a dual agent (then only if buyer's agent paperwork was in place prior to showing that particular property).

In Missouri, I honestly do not understand why any agent would choose to be a sub-agent, because that forces both agents to be equally responsible to the seller. When I am the listing agent, furthermore, I don't want an agent to be a sub-agent when selling one of my listings. I'm much happier with Transaction Agents or Buyer's Agents.

As a seller I never want to be responsible for the action of possibly hundreds of subagents. Having the responsibility to be represented by one agent/company is enough.
How many times have subagents misrepresented a property they don't even know and I as the seller would be responsible and liable for every word they say to the buyer? I don't think so.