Since targets vary in size and distance, both paper and animals, I choose to prepare accordingly; and I don't have to carry all of them at the same time!
Of course I "could live" with only one centerfire rifle (and if I "had to" it would be chambered in 30-06, and of my current rifles it would be my Tikka T3 lite because then I figure that I would be carrying it); however, I don't choose to limit myself to only one and enjoy having a variety of rifles for a variety of reasons and applications.
I like target rifles. I like hunting rifles. I like light rifles. I like heavy rifles. I like small cartridges. I like large cartridges. I like wood stocks. I like synthetic stocks. (I think you can see where this is headed...) But above all else, I like accurate rifles. Not accurate, not in my safe for long.