So first MicroVM != Container, and container is not a secure isolation system. I would not run untrusted containers on your nodes without extra hardening.

The memory forking was originally invented because for AI App Builders and first response driven applications its extremely important that they are instant (difference between running bun dev and the dev server already being running).

However its much more generally applicable, Postgres is a great example of this. You can't fork the filesystem under postgres and get consistency. Same thing with a browser state, a weird server state, or anything that exists in memory. The memory forking gives a huge performance boost while snapshotting whats actually going on at one instant.