> I think it has more of a wide ranging philosophical power or something like that
The Ring was a force multiplier for Sauron (who had in effect transferred some of his power into it, for whatever reason). He could already wield extreme control over his underlings (and we see what happens when he gets distracted at the very end) and strike fear into the hearts of his enemies. All of these capabilities would have been enhanced if he got it back. He would also have been able to perceive the actions (and thoughts?) of the other ring bearers (i.e. the elves). And perhaps a load of other things that Gandalf and the other experts didn't know about (they didn't appear in middle earth until long after the ring was forged).
The Ring was a force multiplier for Sauron (who had in effect transferred some of his power into it, for whatever reason). He could already wield extreme control over his underlings (and we see what happens when he gets distracted at the very end) and strike fear into the hearts of his enemies. All of these capabilities would have been enhanced if he got it back. He would also have been able to perceive the actions (and thoughts?) of the other ring bearers (i.e. the elves). And perhaps a load of other things that Gandalf and the other experts didn't know about (they didn't appear in middle earth until long after the ring was forged).