Doctors are trained to diagnose, think critically and problem solve. Nurses' training is more protocolised with heavy use of guidelines, flow diagrams etc. Nursing is now a degree level course (and many older school nurses will tell you it went to the dogs as a profession when that came in).
NP are like any other hcp group (GP, hossy docs, ward nurses, allied therapists) - you get the really good ones, occasionally really crap ones, mostly middlingly ok ones. A NP is fine for most of the minor ailments people see a GP with. A specialised NP (eg diabetes nurse) is better than most hospital juniors for management of long term chronic conditions.
3 days of antibugs is recommended for simple UTI (lower urinary tract). If you have pyelonephritis (upper urinary tract) problems you need 1-2 weeks.
My husband saw a string of NP who all reassured him that a trace of blood on urine dip was completely normal for a fairly fit young man who cycled / had just got over a cold / had exercised that day. The one that checked his BP also reassured him that 150/95 was normal at 30. The trainee GP he saw for his asthma checkup was the one that diagnosed the uncommon chronic kidney failure, ordered the tests and got him referred.
I still don't think they're all useless because a few of them missed something a trainee spotted. But for every "doctors are crap" story, there can always be the reverse.
Doctors and nurses are a team with different roles and responsibilities within the team. When those limitations on both sides are recognised and worked with, the team works and more importantly patients get better outcomes.