By definition we can never know for sure, but I believe the number of people who stay silent is many times bigger than those who voice their opinion. They've learned it is unproductive (as you say) or worst case, you're told you've got it all wrong technically speaking.
Complaining is not unproductive, it signals to others they are not alone in their frustrations. Imagine that nobody ever responds or airs their frustrations; would you feel comfortable saying something about it? Maybe you're the only one, better keep quiet then. Or how do you find people who share your frustrations with whom you could organise some kind of pushback?
If I was "this government", I would love for people to shut up and just do their job, pay taxes and buy products (you don't have to buy them from megacorp, just spend it and oh yeah, goodluck finding places to buy products from non-megacorps).