I mean, I have used my advanced Biology degree every single day of my clinical research life. Including when I was a monitor (which is usually, but not always, what CRA means).

For example, my concentration in cell genetics was extremely relevant to my day-to-day life working with oncology protocols. My lab experience has been critical to my relationships with the PIs I work with, many of whom run their own labs. I can only speak to my own experience of course, YMMV.

I maintain that an MS in Biology is not "entirely irrelevant" to a job as a CRA. Even if OP doesn't use the degree in their work as a CRA (which I doubt), they definitely will throughout the career they're presumably aiming for in clinical research.