I would be disappointed if I bought something like a math book, and it required me to download a math tutorial program instead of just including the software on a CD because sometimes the website for books maybe offline, or the internet connection is not good at where I am at currently.
Plus, some software like Operating Systems for Windows, and Linux has repair tools like System restore, command line, or an entire operating system stored on a disc, or USB drive, so making a disc or usb version of the software is important for most users who fix their own computer operating system software.
Operating Systems like Windows, and Linux are also many GB in size, so if you have a low bandwidth limit cap like 10GB, it is cheaper to buy the disc version from a store, so you do not have to pay overage fees to your ISP for going over your bandwidth limit.
Plus, some software like Operating Systems for Windows, and Linux has repair tools like System restore, command line, or an entire operating system stored on a disc, or USB drive, so making a disc or usb version of the software is important for most users who fix their own computer operating system software.
Operating Systems like Windows, and Linux are also many GB in size, so if you have a low bandwidth limit cap like 10GB, it is cheaper to buy the disc version from a store, so you do not have to pay overage fees to your ISP for going over your bandwidth limit.