The issue isn't that you assess employees poorly...it is very hard to be right based on knowing someone for a couple of hours...but that it is so hard to get rid of someone if you are wrong. Would you marry someone after meeting for as long as the interview? That is the decision for a lot of companies.
I think that is why you see places like Denmark and Sweden, that make it easy to fire employees, do well and places like Japan and France do relatively poorly (the latter is particularly odd, they had a big lead in engineering...tech is miles behind)...ofc, it is hard to fire people in California...so not every example fits.