Does Bruce Wayne really need Amanda Waller?

The credits scene reveals that Waller knows Wayne’s secret identity. Furthermore, Wayne reveals his plans to form the Justice League, with which he’ll take down Waller and her Suicide Squad if needed. But this isn’t the point.

The question is: Does Bruce actually need Waller’s help? After all, he is Earth’s greatest detective. And if he was able to crack Lex’s military grade encryption, wouldn’t he be able to somehow steal the information from Waller? It would be a better approach, especially since he wouldn’t have to reveal any of his plans.

Furthermore, threatening Waller with the Justice League proves her point – that metahumans are dangerous. And it can only justify Waller’s pursuit of creating a better and more powerful Suicide Squad.

So why does Bruce Wayne need to meet with Amanda Waller to get information he could have obtained as the Batman?