That’s when it all comes down to personal taste. Plus, there’s the legacy. If Slash came out today, he might not ever even get a record deal. Guns came out when it did, touched a nerve for the general populous with their style (though the talent and songwriting can’t be denied) and went down in history.
A7X hasn’t hit that kind of nerve yet, at least not that sharply (and realistically, they may or may not WANT to – there’s a REASON, or many, that GnR imploded), and as amazing as GG is, he’s not remotely accessible. Very few, outside of guitar nerds, have ever even heard his name.
Most people who would know who Paul Gilbert is, outside guitar circles, would only know him for “To Be With You.” Same with Nuno Bettencourt.
What all of them have that sets them apart, is their ear for what’s good, and their unending desire to PLAY.
I think. Hell, I never made it, so what do I know, except as a fan?