Why doesn't Ansible require a central server by default?

Ansible's core design point is that the machine running ansible-playbook, the control node, connects out to managed nodes on demand over SSH, executes what's needed, and then disconnects - there's no persistent server process that managed nodes must check in with or that the control node needs to keep running between playbook executions.

This is different from tools that require a central server managed nodes periodically poll (a Puppet Master or Chef Server), which itself becomes infrastructure that needs deploying, scaling, and keeping highly available. Because Ansible's control node can be practically any machine with SSH access and the ansible package installed, even a laptop, teams can start automating without provisioning new dedicated infrastructure first. For larger, team-oriented setups needing scheduling, RBAC, and a web UI, Ansible Automation Platform (AWX/Tower) adds an optional central server on top of core Ansible - but that's an added convenience layer, not a requirement for Ansible itself to function.