St performs differently based on OS. When tested separately, "linux-st" seems to be at least as responsive as Alacritty, while on Mac OS it's the slowest by far:

https://danluu.com/term-latency/https://danluu.com/term-late...

All that said I currently use Alacritty because benchmarks are not everything and I much prefer Alacritty's font rendering (aside from missing ligature support).