THe data protection officer is the least of the costs they avoid. Medical staff, prevention and protection officer, union representative, ... The list goes on and on. I've heard that a company of 99 and 110 people de facto have the same amount of people doing work, the 10 extra people are all the extra laws that go in effect at exactly 100 employees. SO

There is also impact on worker protection. If your people go on strike, or if you want to do mass layoffs, you just dissolve a few companies.

I presume board requirements are a lot smaller for such tiny companies, too.

Then again, humans struggle to connect, at what, 200-300 people? so maybe it's not terrible to build something like a zaibatsu