Why was the Colosseum no longer used after 523 AD?

The Colosseum ceased to be used for gladiatorial contests and public spectacles after 523 AD due to a combination of factors, including the decline of the Roman Empire and changing social values. By this time, the arena had suffered damage from earthquakes and was repurposed for various uses, including housing and workshops. Additionally, the rise of Christianity and a shift in public entertainment preferences rendered the brutal spectacles of the Colosseum less culturally acceptable. Over time, it fell into disrepair and was largely abandoned.