I worked in telecom for many years.
Retail employees would perform sim swaps at locations I worked at for about $250-300. This was circa 2006 so I’m not surprised that people do it for $1000 with inflation.
The reality is that cell phone employees are paid just above minimum wage, so asking them to protect a system that has the capacity for multiple millions of fraud by simply changing a sim is hard.
The good news is that they made it much much harder for retail employees to access your account without your consent. You almost universally need a pin or last 4 of a social to access a customer account now without a manager override.
This is a huge improvement from the time I worked entry-level retail at AT&T when I could see any customer’s full social or tax ID by typing their phone number into the point of sale!
Imagine being 18, poor as fuck, and able to see anyone’s financial information. I was moral, but I knew tons of people who just took out loans as if they were the customer committing massive fraud. It was very hard for AT&T to catch this kind of identity theft. I’m glad systems are becoming safer over time.