Problem: Something must have gone wrong while Windows was resetting/reinstalling itself, because the laptop is now stuck in a boot loop. No biggie: Windows 10 offers the built-in functionality to 'Reset this PC'. What I have: For business reasons, this laptop needed a reset.
TLDR: This laptop is a Dell Latitude 5420 with an NVMe SSD drive - and apparently Windows has lost the driver for that drive? It can't boot, and I can't (re)install Windows on it without that driver.
