“This is my beloved Son, Listen to Him.” The three apostles have a very unique experience of who Jesus really is. It doesn’t last for long. “Peak experiences” don’t last for long.
We have experiences of God, as well. We don’t have ones like they had (at least most of us don’t) but the experiences we have are just as real. We experience God in the Eucharist, the sacraments, Sacred Scripture, and one another.