[BarryMilo]

I don't understand why people are trusting random WP contrib developers with cache anyhow? Is nginx no longer a thing?

[chillfox]

Because a lot of people who run successful WordPress sites have zero systems admin or developer skills at all. They are usually good writers instead.

[judge2020]

Configurablity and ease of use. Many people run Wordpress on cheap, shared hosting and would only have the option of a cache plugin. A lot of WP admins likewise have no command-line experience and couldn’t install nginx without resorting to Google.

[innocenat]

Caching plugin for wordpress still has benefit that nginx cannot provide like providing object caching, etc.

[spurgu]

WP admins don't have much control (granularity) over the nginx cache. The options I've seen simply have a single "Purge" button.