I am in France but I think the profession is the same everywhere.
It's actually an incredibly complex profession if you want to be good at it, and not just sell houses, but explain the entire process to people who want to sell their own properties (involving legal issues, etc). The thing is plenty of people go into it without much knowledge and thus aren't very good.
But if you are good at it, the profession almost has the complexity of something like being a jurist or accountant, as you need to explain the real estate sale/purchase process in detail. To be good at it, like all sales, you need to be very good not only technically, but also socially.
As an introvert, I couldn't do it. But I've seen people be very successful working for real estate agencies.
It usually takes a dedicated person that is willing to take months if not years learning the inside of the industry, the real estate laws, etc, to be good at it.
So it's basically one of those Black & White professions out there. You have excellent Real Estate agents/brokers, and you have mediocre ones.
It's not like being an accountant, or general salaried person, which are legion, all paid the same, etc.
It takes guts to be an effective salesman in any industry, but those that are made for that job, make it big, much bigger than accountants for example.
But if you're an introvert, like me, accounting or working in IT dept for lower pay (but stable hours, calm environment) is superior.