In his quotes, Suga mentioned that the law are ambiguous. I think he might meant "labor laws". Up until 2014(?) I believed, there weren't laws to protect minors. Later on, there are laws that do not allow minors to work/appear on broadcast after 9PM(?).
I think he was trying to say that the nature of their job don't fit the current labor laws and so idols are exploited in that way. The way music shows run are incredibly tiresome for several reasons.
1. It take 15-20 hours to record a show. A lot of it has to do with waiting. Waiting for rehearsals, waiting for pre-show, waiting for the award at the end, also waiting for the PD at the end of the day to bow to him as he passed by.
2. Back in 2009-2010 when JYJ sued, some news came out and stated that each group only get $400 per show. Then when Kris sued SM, I remember there were discussion that it's still $400-$500 per show. The cost of makeup, clothes, and staff for each of these show can cost to the thousands. Makeup alone can cost $1000, then clothes. All these are promotional expense that is added up to the idols debt, which started with trainee debt. Big 3 companies have done away with trainee debt, but promotional expense is still taking out of idols' paycheck.
3. Last year, I believe that news came out that these shows collect Youtube money for the performances they upload but they kept all of it because they own the copyright.