The kernel OOM killer has never done an adequate job for me. It tends to hesitate to kill anything until the system has literally been completely 100% unresponsive for over half an hour. That's completely unacceptable. Killing a cgroup before the system becomes unresponsive is a million times more desirable default behaviour for a normal desktop system (which Ubuntu Desktop is).

Of course, if it's absolutely not compatible with your work, you can just disable systemd-oomd. I'm wondering though, what sort of work are you doing where you can't tune stuff to use 95% of your 1TB of memory instead of 105% of it?