For what do I need WWISE?

I dont understand what exactly WWISE does. Do I need it, or am I ok with Unreal Engine Audio and my DAW software? What are the advantages of WWISE, if there are any? What exactly can it do what others can not, what are the applications for it? Does it still have relevance today since UE4 got a new Audio engine, has Steam Audio support etc?

Thankfully we don’t need it. It’s already hard enough getting a non commercial license that lasts and it’s such a pain to use.

Wwise provides an audio behaviour authoring tool that is considerably more flexible, sophisticated and efficient than the native Unreal Audio Engine.
It is free to use on small independant projects, and it takes a comparable amount of time to sign up for downlaod and install wwise and register a project and get a license, as it does to get Unreal Account, and engine installed.
If your audio requirements are simple, and you don’t require the polish of your playing experience to be at a AAA standard and you do not have good audio design skills then it is probably not for you.
If you don’t have the skills to leverage Wwise, find someone who does, your project will be better for it.
If you want sophisticated realistic audio, then it is incomparably easier to achieve this with Wwise, as extending the functionality of Unreal Audio to match that of Wwise is significant. In a majority of cases, it would be a better use of valuable programming resources to purchase a license of wwise if making a commercial project than to devout the resources to reinvention of the wheel. There are a lot of programming many years invested in Wwise.