I've done a fair amount of work with employee survey data as an HR data scientist. Particularly at large companies it can be pretty useful, but executives often like to reinterpret the reports they are sent in interesting and creative ways.
There is a quasi-legal standard for creating and validating pre-employment assessment (https://www.apa.org/ed/accreditation/personnel-selection-pro...) but there isn't a lot of regulation and there are plenty of sketchy startups happy to sell low quality assessments to middle-managers at companies with poorly run HR departments.