IQ tests have a 95% confidence interval of about 10, so it's a bit more accurate than you're implying, but still a range of a good fraction of a standard deviation. (basically, the measurement is about 5 times sharper than the variation in the population, so it's for sure a blurry view but they do give you a meaningful idea of where an individual sits in that distribution)

My test only provided at a 90% CI. Not like it is a substantial difference, but I thought I’d throw that out there.

Then again, the same psychologist told me that the discrepancy between my scores was so large that a true FSIQ cannot be used. In a sense, he told me that based on that test, I didn't actually have an IQ that could be accurate measured based on that given test. Apparently, it’s not normal to have almost two SD between some scores...

Being a smart idiot isn't easy work, but someone has to do it.