Higher companies have higher goals. Their picture is big and wide. Therefore, they always need plentiful of resources to address their unique requirements. In a large scale organization, most of the important decisions will be made collectively over the table. These decisions we will name as strategic moves. Most of the strategic decisions will be taken in Board level. Every high profiled company has a panel who are so interested about the performances of the company. They always look at the aforesaid wide picture. Their numbers are crucial. The success of the business will be monitored upon the achievement of these numbers.
Board level discussions are purely based on financials. Is it profitable or not? What would be the investment? Can we really make it? Do we have enough resources? What would be the competition? Can we beat that too? These things are more commonly discuss in a boardroom.
Every higher management needs financial performances of a company to evaluate the success of their managerial styles. To determine whether the given instructions have been implied and practiced. That is why most of the companies do hire separate accounting firms to prepare those specialized documents.
As we said bigger companies have bigger pictures, they also have bigger roles, such as responsibilities when it comes to external environment. Are you a good or an ethical industrialist? Do you follow the right practices? Do you pay your taxes on time? These things are really important for such businesses. And in the other hand, bigger businesses get certain bigger discounts and benefits from the government of that country too. As they are directly contributing to the economy of the country and wellbeing of the citizens, government also provides them certain tax concessions too.
Therefore, in order to handle their income taxes and other levies, most of the mass scale companies do hire tax accountants, who have been trained and educated to perform such duties. These expertise know what exactly needs to be done when it comes to taxation matters.
A business is a crucial responsibility. So your grounds should be clean and clear for you to play in the safe sides. Financials are the biggest asset of a company. Therefore, if it is not maintained in the proper manner, operations can be difficult too. Every company has a separate finance division to fulfill their day to day financial requirements. And also they hire outsourced parties for special situations, such as auditing purposes and etc. 
Transparency is important for any kind of business at all level. Are you doing the right thing? Show it to me? Therefore, be safe and sound always!