EMS in many organizations is being strained. This is from increased run load, abuse of the system, continuing educational requirements (time required to maintain licensure), and firefighter burnout.
For the most part, when circumstances require a response from local government and there are no clear-cut options, the fire department often is the default agency.
The electronics on cars are very sophisticated and require responders to have some working knowledge of them. Added all together, there are no longer any simple car extrications or car fires.