Trading post too close to enemy

Is there a purpose for not being able to build trade posts too close to enemys first tc? I find it kinda annoying that lucky map spawn can sometimes block me from getting all the possible trade posts.

U can’t build anything too close to enemy first tc , so that u can’t be walled in by enemy , or enemy make outpost too close to ur tc , as most civilization get free outpost wagen by age up

Understandable but is there specific reason to block trade posts? IMO blocking trade posts can only give players unfair advantage since you have “monopoly” on trade posts as long as your first tc stands. Due to this, there will not be any competition for some trade posts which I find a bit weird in a game like this.

It’s map issue , tp must be too close to enemy first tc