I just remember that, hardware wise, there wasn't a lot of things that could run all aspects of the OS and be 100% with it. The "certified hardware" on the site also looks like it's out of date.
Concerning the certified hardware, few vendors try to make the certification, and also coreboot is required: https://www.qubes-os.org/doc/certified-hardware/#hardware-ce...
Based on hanging out in the support forums it seems like there have been some pretty large groups of new users, honestly I have no idea why many came at once but they did. Of course for a project this small, "large" is relative.
The current work includes making dom0 smaller by delegating the gui to a service Qube.