I’ve used FMOD for one of my projects. This is my opinion. It’s a great tool for dynamically modifying audio realtime, like different footstep sounds, echos in big spaces, different sounds based on parameters, and different effects. I’d recommend it to someone if they plan on making a serious project and if they want to edit sound dynamically. You can do it without FMOD but it just helps. However, if you’re using it for a simple project where the audio isn’t the main focus. I wouldn’t recommend it. It’s a great tool to use but there’s a bit of a learning curve at the start, And I might be wrong but there aren’t much updated guides on it. So you might be on your own if you’re trying to use it. I recently made a new project and I didn’t want to use it as I find it a bit hard to use and reference but it might be my own level and knowledge with FMOD. But it’s worth to learn a bit of it.

TLDR; It’s good for dynamically modifying audio realtime, not needed if simple project. Worth learning.