Complaining about unfair practices doesn't imply that you're unwilling to be tested, hence strawman.

The recurrence of those complaints indicates that the process could be improved to benefit both parties. Everything you listed can be made better for all. The reasons they're not have to do with a mix of convenience, traditionalism, mimicry and other social factors.

Think of all the good reasons companies had to have workers on site a few years ago, but can somehow still make it work remotely today.