I basically just want to continue using vagrant, ansible, and ubuntu on my M1 -- what's currently the best stack for that? I tried out Parallels, but there don't seem to be any reputable and up-to-date Ubuntu images for it.
Vagrant + vmware plugin + vmware fusion tech preview. All open source (and free). It does work on my M1 (e.g., I'm able to spin up 4 Ubuntu VMs on my M1 for playing around with Ansible and deployments. Each VM with its own static IP). Now, you either have to trust on one of the Vagrant images for ARM available on Vagrant Cloud, or bake our own using, for instance, Packer.
Not sure why people downvoted, but I am also missing Vagrant. I need to configure multiple VMs for various testing, and having Vagrant to spin up a lot of VMs, and run everything I need, that is something I would want to see with vagrant and virtualbox again.
Vagrant allows you to configure a script that will create several VMs in the configuration you need. I, for example, use it to create a real Kubernetes cluster with 3 masters and several compute workers.