"which is pretty much the case for most openings that almost no top players play on a regular basis TODAY"
Totally irrelevant.
Fashion and old fashioned don't rhyme with good and bad...
Anyway ylblai, u discuss all alone, not considering what others say (did u read me when i said some strong GM play it nowadays??).
Maybe Spassky's best closed was his wins against Geller in 68 match. Good examples of how to attack kside. Other related is Fischer's take up of Nc3 as a Sicilian response. Again some good games.
"In the 1990s the Closed Sicilian considerably lost its popularity for several reasons. First of all, its previous adherents, such as Smyslov, Hort, and especially Spassky, ceased to develop it, and other players failed to impress with it. Secondly, Black has found clear ways to parry White's active intentions." - GM Dorian Rogozenko (2003)