I was a little skeptical when I became a Roon user but now I would hate to be without it. Rather than add complexity, I think it adds simplicity in managing your music.
I don’t use the DSP features, but I know many who do and are quite happy with the performance. I have a high-quality dac With its own music management app, which is very good and going back-and-forth, there is no difference in the sound quality. For me, it greatly enhances the listening experience, and I think most who have tried it have found that to be true. As with most things in this hobby, I suppose that’s subjective so your experience might be different. Roon has helped me discover artists I enjoy very much and would likely never have found otherwise. For me, that’s the greatest benefit.