If you have to use a cache plugin on wordpress, it's much easier to use apache instead of nginx because all cache plugins can automatically configure the cache

If you have to use a cache plugin on wordpress, it's much easier to use apache instead of nginx because all cache plugins can automatically configure the cache behavior using automatically generated .htaccess files instead of requiring you to manually configure nginx yourself. Nginx does have speed advantage over apache (and other advantages as well), but if majority of your traffics are going to get served by a static cache, might as well use apache because it's not particularly slower at serving static files compared to nginx, while saving you some configuration headaches.