You can start off with reduced loads and increase the power with age.
Nothing like buying a V8 and then ripping some spark plugs to make it "better" for your teenager....
I have to wonder how many that suggest reduced loads have ever really used them themselves. Having done it, I find it sucks. In comparison to just going with a cartridge that recoils less with proper loads, it's a poor bandaid.
I would rather hunt every creature on earth with a 223 with me picking the bullet, than any 7-08/308 with reduced ammo.
Well reduced 7mm-08 ammo still has way more power than even the most powerful 233 loads. I do think the 22lr is what you should start kids off with and the next step is the 223 but for deer hunting? I know with proper shot placement you can kill any animal with just about any caliber ever made but that doesn't mean it's a good idea to try it.