For a dataset like this, Highcharts would be slower for sure since it will create DOM SVG components for each of the points. <canvas> (which this is built with) is much quicker at presenting tons and tons of data points like this.
Here's a sample chart with 1,000,000 points: https://jsfiddle.net/5bvLgs5w/1/
https://github.com/leeoniya/uPlot/blob/master/bench/Highchar...