I had this issue as well.
I have a Nvidia RTX 3080. After a driver update I did the 'restart later' thing then started Warframe. Warframe refused to load telling me that it no longer supports DX10 and to buy a new graphics card. After restarting my system to get the updated drivers going properly, Warframe launched but re-downloaded all of the game files and reinstalled itself.
Every time I launched it after that my PC rebooted just before Warframe got to the login screen. No warning messages, no prompts, just a straight reboot.
Fixed it my adjusting the graphics settings. It was on DirectX 11 and High Performance. Reset to DirectX 12 (Beta) and Let Windows Decide and the game launched with no crash.
EDIT: Ohhh and putting it back to DirectX 11 / High Performance causes the crash to come back.
