I agree with the sentiment, but I noticed recently that TaxJar (I considered applying there at one point) mandates a trial period along these lines. From https://life.taxjar.com/distributed-team-hiring-process/, "... We hope a candidate is able to spend somewhere between 80 and 160 hours working with TaxJar during their trial. ..."
Presumably there are some people who are willing to do a trial, either concurrent with their existing employment, or on the chance that they will be hired after the trial.