Worried about turnover at prop trading firm

Hello, I recently accepted a graduate quant trader offer at one of the more reputable Chicago prop trading firms. Previously, all my experience had been in software engineering, and I found that the job really didn't satisfy me. I always loved statistics and wanted to pursue a career that seemed more exciting to me, so I decided to recruit for quant and accepted the first offer I received. I'm about to renege my FAANG offer for SWE, but I'm starting to get a little worried. I have 0 previous trading experience and I've been reading about high turnover at these firms. In addition, I started talking to others who are entering my company at the same time and they all seem so much brighter and experienced than me (some of them were USAMO competitors and others have lots of experience in finance and trading in general). I'm afraid that my inexperience might cause me to underperform and that I might be let go. Does anyone here know about how the different prop trading firms in Chicago fire new hires?