A gauge would be able to signal a crashed pump.
When was the last time you heard of an oil pump on a street vehicle completely failing?
The point is knowing that there is pressure in the oil system doesn't help anything except that the pump has not failed.

Look at the pump and figure out which parts might catastrophically fail.

 

I was thinking old small block chevies.

 

Yea, like when the plastic barrel (used in seventies) would break and let the rod drop from the distributor to the pump. HA!

 

Yep, you remember...