PHP-FPM chroot working out of the box, is it normal?

I'm trying, in a dev box (Ubuntu 20.04), to setup for the first time a chroot.

Here is my PHP-FPM pool (Apache 2.4 as Webserver):

[test]

prefix = /srv/users/$pool

user  = $pool
group = $pool

listen       = /srv/users/$pool/run/php-fpm.sock
listen.owner = $pool
listen.group = www-data
listen.mode  = 660

chroot = $prefix
chdir  = /

env[PATH]   = /usr/local/bin:/usr/bin:/bin
env[TMPDIR] = /srv/users/$pool/tmp
env[TEMP]   = /srv/users/$pool/tmp
env[TMP]    = /srv/users/$pool/tmp

php_admin_value[doc_root]       = /srv/users/$pool/app
php_admin_value[upload_tmp_dir] = /srv/users/$pool/tmp
php_admin_value[sys_temp_dir]   = /srv/users/$pool/tmp

With this setup, without further configurations, I'm able to install Wordpress, use their Plugins store (so, DNS resolution works) send emails with a SMTP configured, etc.

Problem (or not?) is that I've read here, or here that several files need to be either copied over or mount --bind on the chroot to these functions to work.

Who can I make sure my chroot is working properly and not misconfigured?