I've run an AR pattern rifle dry plenty, especially in winter. it accelerates wear but the rifle works fine if it's made to spec. lots of rifles are not, and that's where the real problems come in. it's the same deal with 1911s, the fundamental design is sound and then third parties come in and start changing shit and it gets a reputation for being unreliable or finicky

in general three drops of CLP every so often and keeping the dust cover closed is sufficient to keep an AR running, in my experience. and I mean I've literally never had a failure that wasn't related to either bad ammo, or a bad magazine