"On top of that,
it used to be you could bump start a car with a manual transmission
and a low battery but modern fuel injection requires too much juice
for a bump start with a low battery"

There are other problems. When you turn the key on it only charges the fuel system for a few seconds.

And yes, I found out one day that some cars actually use more juice running than starting. Between the ridiculous firing current and voltage, then you got anywhere from four to sixteen fuel injectors. The car would literally crank but not start unless it had a jump.