Why is the article written only for the seven congregations in Asia?

Why is the article written only for the seven congregations in Asia? The number seven indicates completeness. The seven days, the seven candlesticks, the seven angels, the seven stars, and the seven golden candlesticks all represent the perfection of God. Seven Churches These epistles are God's warning to the seven types of churches from Pentecost to the end of time. Although these articles represent each period, The character of the seven churches in each period is revealed in the churches of God.