Containers are a misunderstood technology. People think about them as a privacy feature, but that's far from real. The only benefit of containers is the ability to have different sessions of the same service in the same windows/profile. That's it. A good use case is when you need to work with multiple AWS accounts.
Cross-site tracking is already enabled by default since... 2018? So, using containers as a way of dealing with cross-site tracking is utterly unnecessary.