Your question has almost nothing to do with WordPress. Since it’s “almost”, I’ll just make two quick comments.
First, nginx does not support .htaccess files, and WordPress (and it’s plugins/themes) is fairly reliant on them. Unless you are very good with system-level configurations, nginx is not for you.
Second, Litespeed costs a LOT of money if you want it to run in more than one or two CPU cores. If you have a server with, say, 32 cores, a properly-configured Apache will be faster than Litespeed performance-wise because it’s using all 32 cores where Litespeed will only use a small subset.
Beyond that, I suggest that you ask your question on stackexchange and let the Litespeed/nginx fanboys fight it out. 🙂
you are not the first to have TTFB problem in Litespeed hosting, I also found this problem but topic is closed
https://wordpress.org/support/topic/ttfb-is-higher-with-litespeed-active/
2.0 secs TTFB he got after installing Litespeed, well that is even worse than my case but I found that some web hosts are having too many customers on their same server from cPanel shared hosting can be part of the reason (they tell you to install cache plugins but it can only help a bit)
First, nginx does not support .htaccess files, and WordPress (and it’s plugins/themes) is fairly reliant on them. Unless you are very good with system-level configurations, nginx is not for you.
that is a GOOD reason to use Nginx cuz you will not have any users hacking the htaccess setting or plugins (like Wordfence crashed my site before), cuz with Nginx then plugins can not hack it anymore
but you are right that Apache 2.4 is very good and if you do not use shared hosting (such as Litespeed cPanel) than Apache 2.4 can be amazing performance
really good discussion about Nginx vs Litespeed is from Ask WP and you can understand that Nginx used by high-traffic WordPress sites and mostly 99% of Litespeed is for shared hosting only (slow TTFB)
https://askwp.org/question/litespeed-vs-nginx-is-litespeed-more-powerful-than-nginx/
stop caring about benchmarks stuffs, just use what is faster in your browser and that means good hosting and settings, but my experience Nginx is best
LS cache plugin is large codebase too many bundled script. I could suggest WP Fastest Cache and WP Super Cache for more lightweight cache plugins.
problem is Litespeed want to use only their product (LS server and LSPHP and LS cache plugin also)
that is not friendly with open source community.
Apache is the most reliable and Nginx for open source web server and can use any PHP module and cache plugin too! pls stop rumors about Litespeed
