Yes I believe that personality test are a legit way to know someone personality.
No I believe that personality test do not work.
Took the Jung Typology Test and got INTJ. I felt like it describe me accurately. Hard/rarely seen outside of their workspace or home. Not very social. But analyses a lot of things and over thinks things.
Most personality tests do not work, or at least not for me. Some get close but never 100%.