Low oil doesn't tell you engine is dead, it tells you of an impending danger that engine may be damaged. There are any number of actions driver can take.
Same for tachometer - red says you are outside design optimal parameters and you should take an action (slow down) rather than risk possible impending engine damage.
Neither is "bad thing happened, it's done, there are no actions you can take any more" in my interpretation.
Low oil doesn't tell you engine is dead, it tells you of an impending danger that engine may be damaged. There are any number of actions driver can take.
Same for tachometer - red says you are outside design optimal parameters and you should take an action (slow down) rather than risk possible impending engine damage.
Neither is "bad thing happened, it's done, there are no actions you can take any more" in my interpretation.