I use Wavelab as my main sample editor. I hardly ever use the montage or other mastering oriented features. But the audio editing features are worth it to me.
Mostly use it for preparing samples for vst instruments. You can do all the basic editing like trim, gain, fades, loop markers, effect processing if needed. It has a powerful batch processor.
The other case I find it useful is with video editing applications. Open the audio in Wavelab, check and adjust the loudness, denoise either manually or using plugins. You can also use external editor from within Wavelab, for example RX or SpectraLayers. So I do the basic edits and clean up in Wavelab and then use RX or SpectraLayers if needed. This is very material dependent. Sometimes putting a denoiser plugin on master does the job. Other times it might be a short region that needs some noise removed.
So Wavelab is definitely not just for mastering.
I only have RX elements. I rarely use it as editor. But I find the plugins quite useful.