All the big brands make a lot of similar lenses. Sony, Nikon and Canon all have their own 50mm and 85mm f1.2. All are extremely good optically, very large and costs about the same.

But what (unique) lenses are there that really differentiate the brands?

Here are some:

Canon:
> RF 28-70mm f/2L
This looks like quite the beast, and would possibly be the only lens a lot of photographers would ever need. You can shoot everything from landscapes to astrophotography and portraits.
> RF 16mm f2.8
Cheap, small and light weight. It also has pretty good image quality. No other brand makes a lens like this, and it may be the only option for wide angle shots a lot of photographers need.
> RF 24-240mm f/4-6.3
While not super cheap ($899), you get a lot of bang for your buck. This is the best 10x zoom ever made and the image quality between 50-150mm is excellent.
> RF 100-400mm f/5.6-8
Only $600(!). It is supposedly very good when it comes to IQ (on par or better than the 150-500mm Sigma C). Very sharp. It is also very lightweight and compact for being such a long telephoto lens.
> RF 600mm & 800mm f/11
Two truly unique lenses given their relatively small form factors and small price tags. Apparently they are also reasonably sharp.