The recent FOSDEM 2019 meeting had a great presentation on Crostini:
https://fosdem.org/2019/schedule/event/crostini/
Crostini is now part of ChromeOS and so is available in many ChromeBooks allowing those users to run Linux applications.
Crostini is built on LXD so its good to understand that large user base and where Crostini is headed.
Specific mention of LXD is around 9 min 30 seconds into the video but I’d watch the whole thing.