I think the issue is more about what else has to go into or be connected to that container. Posthog isn't really useful if it's air-gapped. You're going to give it keys to access all kinds of juicy databases and analytics, and those NPM tokens, AWS/GCP/Azure credentials, and environment variables are exactly what it exfiltrates.

I don't run much on the root OS of my dev machine, basically everything is in a container or VM of some kind, but that's more so that I can reproduce my environment by copying a VMDK than in an effort to limit what the container can do to itself and data it has access to. Yeah, even with root access to a VM guest, an attacker they won't get my password manager, personal credit card, socials, etc. that I only use from the host OS... But they'll get everything that the container contains or has access to, which is often a lot of data!

Because you need your application code to interact with Posthog's code. But if they're running in separate containers...how are you doing that. Surely you are not writing an api layer for every npm dependency you use.