Turns out it is an App Armor restriction that Unity hasn't mentioned anywhere in their documentation even though we are at LEAST two releases into this problem. The fix is simple, but should be part of the install docs.
This is the error for the search engines:
No usable sandbox! Update your kernel or see Chromium Docs - Linux SUID Sandbox Development 48 for more information on developing with the SUID sandbox. If you want to live dangerously and need an immediate workaround, you can try using --no-sandbox.
To Test:
sudo sysctl -w kernel.apparmor_restrict_unprivileged_userns=0
And then for the real fix: /etc/sysctl.d/unity.conf
kernel.apparmor_restrict_unprivileged_userns=0