Maybe I'll just jump in with one comment.
I disagree with the commissioner's concern that the need to prove substantial lessening and prevention of competition is a burden that he ought not need to discharge. This specific context of the grocery hero pay was a very unique situation in the labour market. That was a situation where basically every store other than grocery chains was closed. In that specific context, one can imagine that this type of wage-fixing agreement indeed had an anti-competitive effect on the labour market. Those workers would have nowhere else to turn for another job opportunity. They would not have had the opportunity to get another job with higher wages elsewhere.
In the hot labour market as it is right now, with an extremely low unemployment rate, the agreement between some employers to fix wages would, I suggest, have a limited impact on employees' actual welfare, especially for employees with generally transferrable employment skills. Those skills can be easily transferred to another position. The alternative employer doesn't need to be in the same industry. A grocery worker probably would be using a very similar skill set as someone in another retail context.
When we're thinking about competitors in the no-poaching or wage-fixing context, it is about who is competing for the same types of employment skills, rather than competitors in the supply market.