> Too expensive to perform daily tasks - open souce models are much cheaper

There is a real advantage, especially for businesses, in using an off the shelf solution from a corporate provider.

Personally, the advantage of not having to set up multiple solutions from multiple sources outweighs the cost of a $20 a month subscription. Think about why a lot of consumers prefer Apple devices over Linux. There are a lot of advantages to Linux, but "never having to think about my tools" is its own advantage.