What can nurses do that doctors cannot?

If you are asking this question regarding scope of practice, doctors can legally do anything nurses can.
If you are asking regarding work, doctors cannot change specialties and work in different areas as easy as nurses can. An internal medicine doctor can’t suddenly go and work full time in an ICU without some form of fellowship in critical care or pulmonology etc

Draw blood.. Do wound care, be patient, have a poker face, clean up after they have made a mess. Be very empathetic. Ha ha, I'm sorry, but it's true. We have endurance that they could never manage. Go home and do it all over again. Basically all physicians can do a lot. But their workload is incredible. That's why there are nurses.