Amazon QuickSight now supports 10,000 data points for Line charts. With this update, line chart performance has been improved to support 10,000 data points from the earlier 2500 data point limit and introduces other minor bug fixes.
This is a companion discussion topic for the original entry at https://aws.amazon.com/about-aws/whats-new/2022/05/amazon-quicksight-line-chart-support-10000-data-points/