A district-based system for choosing representatives has issues in-and-of-itself. Those issues become applified when you ask the questions “who draws the districts?” and “how often are districts redrawn?”.
All too often the answers to these questions indicates systematic abuse of power by those that are in power. In the US both the Republicans and the Democrats have a long history of abusing redistricting.
In fact, it goes back to before these parties existed. Consider Governor Elbridge Gerry of Massachusetts.