There are people who are well paid in there company,which allow them to be able to save well to gather enough money to buy assets properties without owning a business.
but buying assets and investing in business both are different, and assets have also different categories, some assets you have holding for lifetime but no passive income here, but business is a passive income source, and if you will success then you can buy another assets from your business profits, that's major advantages in business.
Buying of assets also relies on its market value. Like people in the real estate business who buy assets at a lower rate and sell higher in few years. There all fall under business, and could be used to strengthen both running a business or purchashing of properties or assets. Moreover most successful businessmen run the two to maximize profits.