Can someone keep their job as a real estate agent if they only sell 2 houses a year?

I can't see any realty company maintaining a spot for an unsuccessful realtor in their business.

It is not a job. It's a profession.  You are not paid wages or a salary or benefits.  You are paid on commission, with a share of the total commission earned on a purchase or sale going to the broker that agrees to hold your license and take legal responsibility for your actions. Actually, you cannot be paid a commission directly until you are a broker AND own the brokerage. Until then, your broker earns the commission from your transactions and pays you the agreed-upon commission split.

If it's all you do, you can't earn a living on two deals a year.  But many large brokerages operate on volume and don't care how many deals you do.  They make money on every deal and it's strictly a numbers game for them.  They'll agree to hold a license for a new person, figuring that person might buy a house or sell a relative's house and then might give it up.  They do not invest much in these people in the way of time and training and are happy to take their cut and let these people move on.

Other brokerages demand performance and will not keep holding the license of a non-performer.  But this is not exactly a hire/fire situation.  You are an independent contractor. Either you or the broker that holds your license can end your relationship at any time.

Maybe. It would depend on the prices of the houses they sell.  It's much different to sell 2 $5,000,000 houses than it is to sell 2 $200,000 ones. Since most agents are independent contractors, it would be at the agencies' discretion.

If they're paid commission only, some firms would keep them, especially if the market was moving poorly, which is not the case now.