It depends on the subject, how the CEO is known to react (perhaps the CEO is not from here), a trainee might hold back a little bit more, and more such factors do of course play a role.

Our organisational structures are generally just as flat as our landscape, which might help promote more opportunities for people to speak their minds to upper management. I don't have data on this though.

A distant relative of mine always said his business would have never started making money if it weren't for the Polish ladies who worked in his factory complaining so much about their work areas. He had his lunch in the general cafeteria together with everyone else whenever he could, and that is not uncommon here.

Edit: We also have a concept called "medezeggenschapsraad" or "ondernemingsraad" (depending on context), which is a kind of employee panel with decision making power that businesses of 50 employees and up are required to have. Unsure if this is unique to the Netherlands though.