I think business follows some very clear rules, compared to friendship. It’s always about money. The decision is always in the direction that is the cheapest and brings the most profit. Friendship can help there, if some options are equally priced, then the friend may be chosen, because of the friendship.
I think employees have a very powerful position, once they realize that. Replacing someone can cost up to 6 monthly salaries (fees for headhunters, trainings, …). If you find out where the tipping point is, you can negotiate better. It’s also important to highlight your employers benefits if you want something.
In corporations then currency is quite often not just money, but influence and power. A lot of managers decide based on what will give them more power. If you play along, they may give you much more money/benefits.