I think all tactical-defensive semi-auto guns should come standard with 4 magazines. Rifles or pistols. All calibers.
If it's intended to be a fighting weapon, you KNOW that people will want at least a few extra mags for it.
Ditto if it's just a range toy for action shooting matches. We all know those games involve mag changes, and if you have a malfunction or accidental drop of one mag, you'd better have more ready to grab.
That's one thing I like about Ruger .22 pistols-- they call come with 2 mags. That's what you need for most shooting games or bullseye matches. When I bought a Browning Buck Mark, it only came with one mag, and the second one cost me $33 after shipping.
Lol, why give it away when people will buy them. Regarding ARs, some folks have their own brand of choice, metal or poly, Pmag or......