Depends what your modular sounds like
It’s a hard question to answer.
It won’t sound like a Piston Honda or SWN, and it doesn’t have a Mimeophon or Euclidian LFO’s. Similar to what @SoundRider is saying.
But if your rack is mostly subtractive mono synths and traditional effects then yea absolutely!
It’s kind of its own thing IMO. I’ve recently picked one up and currently it is being used in place of my rack - so I won’t knock the question, but it works for me primarily because my voices can be largely replicated on the A4 and I don’t make West Coast stuff. I’m also playing with a Minifreak at the moment which also covers some of what my modular does.
Biggest difference for me is the lack of knob per function - A4 is a lot less hands on, it’s something you program rather than patch, which is a very different experience. Although the Performance mode helps cover some of that in a nice, non-destructive way. Plus patch recall. It’s a very powerful box but for most people I’d see it more as a way to consolidate desktop mono synths rather than a traditional modular setup.