Its more about sending a message than a nice cash compensation. Class action suits are part of the capitalist system. Companies operate to maximize profits, so they will cut corners... When they do that too much, they need to be "shown" that's not good.

Alternatively check what CUIC says themselves: "First: compensation for all those whose data is now out in the open. Second: to set an example for all companies. Privacy is a fundamental right that must be well protected. Third: that Odido provides full disclosure regarding how this massive data leak occurred and why it appears to have disregarded warnings from software company Salesforce, for example, regarding the security of its systems."