> If you have even more than just 1 deployment of a thing and scale to 2 (or N), you now also have to manage the software level of those N containers (without multi-tenancy) vs. just 1 deployment for everywhere.

Sometimes this is a feature. If you're doing managed enterprise SaaS then you frequently need to have different customers running on different releases for whatever reason (maybe one customer has a difficult data migration that has to take place before you can upgrade, maybe another customer has something custom that needs to be upgraded in sync).