Please describe how you plan to use ansible to deploy config in ~200k containers, with hundreds of data updates per day

I would not use containers in the first place as this adds added complexity and overhead in the first place.

Please share how to manage ~200k applications without containers

The real "fish out of water" question is "tell me how to use Ansible to configure 200k embedded appliances where the end customer doesn't always allow firmware updates through their firewall?"

Ansible will be terrible slow to update things if you're geographically far from the servers. Updating around 100 servers from another continent already takes longer than a 5 minute TTL. Parallel connections only work up to a point before a playbook run always have at least one failure and requires a re-run.

Ansible also does not have locks or parallel users coordination, so you’ll need a single user/VM/GHA workflow running the playbook or at some point concurrent users will start overriding each other.