Also see: https://makeitwork.press/litespeed-vs-nginx-benchmark-wordpress/
“There were a lot of posts from niche blogs and not so-great-looking blogs claiming that LiteSpeed performed up to 1200% better than Nginx showing some nice LiteSpeed vs Nginx benchmarks. That sounded like a story that is too good to be true, but could it be really true?…”
“If we compare OpenLiteSpeed vs NGINX, I think Nginx is the clear winner in terms of performance. It’s only a (big) pity that they don’t have a plugin as good as the LiteSpeed cache plugin.”
Pretty good write-up although I disagree about the LS Cache plugin, which is a bloated mess and sure to cause issues, esp. if your clients touch it
Caching should always be server-level only for best stability = Nginx FastCGI cache, no WP Plugins cache required.