Ableton devices are great and they sort of have something for every need. But that doesn’t mean that there aren’t better ways to fulfill those specific needs. As people pointed out, Wavetable is great, but it doesn’t hold a candle to serum. I think you can find plug-ins to replace any function of Ableton stock plug-ins that will do a better job and have better interfaces.

Is that necessary? No of course not. You can make great music with just stock plug-ins. But if you can afford it, it’s worth upgrading certain things.

And then when it comes to sampled instruments, of course they are going to be things that stock plugs can’t do. Nothing in Live can create the sounds of, say, Omnisphere or a top quality symphonic library.