For those of us not familiar with lxd, could you summarize what it's presently mainly used for? It looks to me like it's a container system with a higher level of isolation than lxc, but is it principally interesting for deploying server software in a VPS-per-machine to try to limits the impact of a compromised server? Playing video games from unknown and potentially-untrusted sources? People reselling VPS service?
Skimming the tools page, I'm guessing maybe a little of #1 and a little of #3, but couldn't say for sure.