alt Hacker News9P is very slow for certain operations (such as, for example, git from either direction).
virtio is not enabled by default because its buggy in certain corner cases, and will be enabled by default when it stops doing that. That said, I do have that enabled, it is certainly faster.
Since nowadays I use WSL to run immutable containers, and not really classical Linux Desktop, it isn't something that bothers me.
Agents take more time than building Docker images.