How is the contrast between ancient and modern Italy articulated in Byron's Childe Harold's Pilgrimage?

In "Childe Harold's Pilgrimage," Byron begins by establishing ancient Italy as a place of wonders where gods walked the earth, whereas modern Italy is, by contrast, no longer a land of legends. The speaker has "sighed o'er Delphi's long-deserted shrine," which is now "still." He is unable to "awake the weary Nine" to participate in his "plain" and "lowly" story.
Venice, which Byron personifies as a queen "sate in state, throned on her hundred isles," is proud, majestic, and looks to the speaker like a ruler, but he points out that this is no longer the case. Venice's is a "dying glory," harking back to a lustrous age of extravagant wealth. Byron underscores this through the use of lavish descriptive language: "the exhaustless East/poured in her lap all gems of sparkling showers," the adjective here emphasizing the sheer enormity of Italy's former wealth. Now, "Tasso's echoes are no more," and the beauty remaining in Venice, which does not "decay" with fallen states, is that provided by Nature itself.