To put it simply, because it’s too big that the economy of the country is depend on it. If the company failed, massive amount of mid/high income people would lose their job, and this will affect the country’s economy so badly it could potentially crash it. That’s why country constantly bail out big company, its to protect basically everyone. Except when other country bailing out a company they nationalised it in some way.

When the rich say trickle down economy, this is the stuff that is being trickle down, not the good stuff that benefits everyone.