Looking at some rough figures from 2020 after a quick Google search
Total sales albums Korea and Japan : 1.6 million
2019 Tour 83,000 attendance.
Merchandise sales ???
Say we cost an album at $10 each, in 2020 alone IZONE could have generated $16 million in sales.
No idea what concert tickets are but let's conservatively put them at $25 a ticket = $2 million
Lets take a total guess and say they raked in $1 million from merch sales.
If we say post Co Vid in 2022 they can tour again (demand will be off the charts as well), make a similar amount from concerts and albums that's basically looking at $19 MILLION!!!
What are the costs, maybe $1.5 million on staff, $1.5 million on MVs, feeding them, clothing them $1 million, add another $1 million for other stuff flights, cars, Sakura's gaming PC etc = Cost to run IZONE is $5 million per year. So with the $19 million say knock off a few million in taxes we are now looking at maybe a $9 million profit at this point.... $500,000 sent to each company for the member knocks off $6 million leaving a clean $3 million to the owners/ creators of the group!
What went wrong here if other companies were willing to sign up - I can only assume say Starship if they were given this ballpark figure believed they could make more than that with two star idols in Ahn Yujin and Jan Wonyoung. Or that they were fully aware of the revenues and didn't feel the cut they were offered reflected that.
My figures could be way off though maybe they ate loads and that drove up costs :-D