As a user, you don't really need to care about the number of containers since everything is managed by docker-compose or k8s (soon). The advantages of having more containers is that you can have specialized softwares. For example, the search system is based on meilisearch which makes it way better than what could have been done by just using postgres/sqlite. It also makes distribution or replication built-in (for example, to have a transcoder on a remote computer), jellyfin/plex does not support this natively and users have written their own remote transcoder for that.