Yeah, it’s a big and raging and ongoing debate about the ancient world’s mystery people. The pendulum moreover swings back and forth academically between the autochthonous and eastern migration camps, too. I post now to see how the historians here at Reddit view things. I’m at my wits end drawing my own conclusions. Like the pendulum I swing back and forth and even Michael Grant, one of my big heroes, doesn’t seem to provide any solution. I will offer three things that fascinate me. First, the Etruscans had the best real estate in Italy. First come and first served. Second, unlike the other people who migrated into Italy (pre-Magna Graecia) they were the only ones who had a seafaring tradition. And third, their ability to divine things speaks of techniques only known in Babylon.
Short answer: It's still unknown
As you said it's a lively debate and there are many theories. I guess the most intelligent answer is that it's a mix of everything. It's quite possible the Etruscan people originated in late Brone Age Anatolia as the Etruscan language is not related to indo-european and has more ties to the Near East. When it comes to archaeology though we see a strong connection to old Italic burial rights that are way older than the presumed migration to Italy. I think the Etruscans as a nation itself definitely formed on Italian soil as a kind of melting pot between Italian and foreign (Anatolian) people.