Ignorance is bliss, I can't believe I used a 223 for 30 years to hunt an do control work let alone using a 22H, 218 Bee and 222 to kill coyotes.
Just as interesting I haven't had a working 223 around for about 15 years now, I've got a couple of new 223 barrels on the shelf but nothing I can actually shoot. There wasn't a thing wrong with the 223 it just got boring, so it was on to more interesting things like 22-204, 5.6x52R, 5.6x50R Magnum and 6.5x58R Sauer and for tossing LF bullets at coyotes a 6mm-204. I find making the strange stuff work a lot more fun and satisfying.
I would never consider anything under 25 cal for a deer rifle with a 7mm Mauser 175gr RN, 375 Win 250gr and 35 Whelen 250gr RN ideal, but that has more to do with my hunting style than anything. I still hunt and track deer in heavy cover, rarely getting a broadside shot and having to take what ever shot is available meaning I have to have enough gun to reach the vitals from any direction.