Details of www-servers/apache:

Warning: Critical module not installed!
Modules 'authn_core', 'authz_core' and 'unixd'
are highly recomended but might not be in the base profile yet.
Default config for ssl needs module 'socache_shmcb'.
Enabling the following flags is highly recommended:
+ apache2_modules_${cmod}
Info: Missing load balancing scheduler algorithm module
(They were split off from proxy_balancer in 2.3)
In order to get the ability of load balancing, at least
one of these modules has to be present:
lbmethod_byrequests lbmethod_bytraffic lbmethod_bybusyness lbmethod_heartbeat
Attention: The tls module based on rustls-ffi has been moved to its own package.
emerge www-apache/mod_tls to continue using the tls module.