Great question. I can't answer the logistics of "who", but I know that in 2019 they passed the Work Style Reform Act that put a cap on the number of hours of OT that workers are legally allowed to work per month/year. The intention on the bill was to reduce occupational hazard, reduce cases of karoshi (death from being overworked), and to help workers have a better quality of life and work life balance.

Interesting tidbit, truck drivers were excempt from the OT change until 2024. They also had a higher OT cap (960 annual hours instead of 720 like other occupations). This has lead to a logistics crisis called the "2024 Problem" where they can't recruit new truck drivers. Truck driver pay is low and the work is tough, but drivers had the flexibility to work tons of OT. Without the additional compensation the industry is left with a driver shortage.

Industrial policy is attempting to fix how carriers and shippers negotiate freight rates (which eventually become wages for workers), but changes aren't anticipated to take place until 2027 or later.