That chord voicing is not JUST an open G riff though, it had seen widespread use long before that, not least featuring in 19th Nervous Breakdown a few years prior, the live version of Sympathy for the Devil and Under my Thumb from the 69 tour, the list goes on. You just omit the A string....as you mention. In fact in all of the songs above its EXACTLY the same chord(s)!
Oher artists songs that
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