Probably, if you are a PROFI, the lens will not be quite enough for you. I was able to use it during a safari in Namibia in December/January. I am very satisfied with it. In wildlife photography, speed is not necessarily important. Focusing was always enough for me. The thing is just a bit heavy. But for this price, I can recommend it.

Addendum: I use the lens on an EOS 7D

I only have experience with a 5D MK IV. The lens (I don't have the Sport version, the name Sport for the lens is misleading, it is the Contemporary version. It's probably a mistake on digitec's part) should work fine on the 90D. The AF of the Sigma is nowhere near as fast as the AF of the Canon EF 100-400 f/4.5.6 L IS II USM, for example. I recommend the Canon 100-400 if you need a fast AF. You won't be happy with the Sigma in this respect. With the cropfactor of 1. 6 with the 90D you also have 640 mm focal length. The Sigma is another 500-600 g heavier and bulkier. The imaging performance of the Sigma is very good considering the price, but at 600 mm focal length you have to stop down to at least f8. You won't get crisp results with open aperture.