At a high-end restaurant I used to work at, the head chef would routinely get people in for 'trial shifts'. Min 10 hour shift. He never had any intention of hiring any of these skilled kitchen workers, just wanted to steal their labour to get ahead of the week. I'm pretty sure word spread that he did this, but people wanted to work there cause it had a Michelin star.
It seems every hospitality job these days requires a trial shift. Like sure, if it's a closely knit team under high pressure, maybe get people in the same room. But not every single job. Not in place of an interview. Not for hours and hours. At that point you are blatantly exploiting people already in a vulnerable financial opinion.
I'm applying to places now and have been asked to work a trial shift for a bowling alley. A fucking bowling alley?? They told me it would last an hour on the phone but an automated email said 'around two hours'. Well, I can't do two hours, so I guess I'll be leaving early. I would seriously be considering not doing it at all, if I didn't need to prove I was taking 'any opportunity for work' for universal credit.