Thanks for your fast reply!
There seems to be a bit difference when opening a RAW file in Apple Photos and Affinity. As you can see on my new attached screenshots, in Apple Photos, the RAW and the JPEG is behind the same thumb, and then I can toggle between the two after selecting the thumb, much like in Aperture.
So I won't have to open the RAW through Finder to get it displayed in Apple Photos.
If I try to find the RAW in Finder to open with Affinity though, the CR2 files won't show up at all either by searching or browsing - even though they do exist in my computer as they are readily available in Apple Photos (and used to be readily available in Aperture before I deleted that).
So I still got no idea how to open any of my RAW files in Affinity.
Thanks!