It takes several persons to properly man a fire fighting team. I'm guessing a minimal of 7 but closer to 9 when you count for men needed to drive the pumper from hydrant to tanker.
In the Navy we used six men just for manning the hoses. A fire hose at operational pressure is not like watering the garden with a spray nozzle. The stations are a necessity because in a fire TIME is an enemy. The longer it takes to respond the larger the fire. More modern buildings pose less a risk but still a risk. Older homes and especially older commercial structures even with sprinklers pose significant issues that can easily tie up several companies. They are often homes to vagrants who start fires.
Two fire fighters in the city south of me nearly died in such a fire. One took years to recover to where despite the odds against him about 5 years later recently passed his re-certifications. Certification is everything. Even VFD's must have them. It takes time and money. Not many persons have the time nor skills needed to be a VFD. If you do not have the skills and training you can get yourself and others injured or killed.
FD's respond to wrecks for several reasons. Extractions, fuel spills, First Aid, and other needs because common sense dictates better to be there and stop an incident than loose time that happens before someone on scene arrives from another agency to assess the scene. The may also be dispatched and told to cancel. This is an occupation where Seconds Matter.
We have seen improvements and better outcomes thanks to technology increasing and an increase of organized fire departments. Buy a police scanner if you think your money is wasted. Listen to what goes on. Do you know for example an ambulance for your area may be at the hospital and 15 minutes out but the FD less than 5? You're having a heart attack or your child is choking? What time frame do you wish?
Finally Fire Departments response times are looked at by insurance companies when setting home owner insurance rates. That and the FD's equipment and skills.
Fire Fighting is by no means a safe nor risk free occupation. Never has been and never will be.
The risks in firefighting are always evolving. Car fires and extractions can be very dangerous now, side airbags and electric hybrids pose new dangers along with all the new synthetic materials that emit more toxic chemicals than in years past. Brush and wood fires are very physically taxing because of heavier gear and difficult terrain, they would rather fight structure fires. Every older Fireman I know has a bad back from years of dragging hose and wearing heavy air packs.