Weren’t the Gospels written a long time after the events of Jesus?

Weren't the Gospels of Jesus written a long time after His life? The final form of the Gospels were most likely written around 30 to 60 years after the events they record.

This may sound like a long time, but it's actually inconsequential.

The ancient world was predominantly an oral culture. Historical events were commonly and accurately transmitted without being written down. But details of Jesus' life were eventually written down, 30 to 60 years later,

because the eyewitnesses were dying out and the believers wanted to preserve their testimony.

But most history is written many decades after the events and we never think to challenge its authenticity. Laurence Rees published a book on Auschwitz 60 years after the Holocaust, yet no one suggests that this history is invalid. Otherwise, no history could ever be written.

The Gospels were written later, but this timeframe doesn't diminish their trustworthiness at all.