[jonjojojon]

This is the default solution for anything even slightly complicated. At very high frequencies(Rf), then you may be forced to use passive filters. The range where it makes sense to use active op-amp filters has shrunk considerably.

You get ease of prototyping,modification, and excellent performance. In these systems there may be still analog filter components(anti-aliasing,reconstruction), but with digital components so cheap,good, and fast this "mostly digital" technique is almost always the best option.