Unlike a car, which can just stop, a plane will crash if you lose control. It has no other option; even if it did recover to straight and level flight automatically, it would just fly off until it ran out of fuel/battery, and crash somewhere else. You're much better off having the plane crash in the flying area than flying off and crashing into someone's house several miles away.

The vast majority of planes have no failsafe system built in. You can get a more expensive radio with PCM, a digital encoding with a failsafe, but it can't recover the plane because it has no idea what direction the plane is going. With PCM, you can only program how the plane crashes. There are also autopilot systems on the market now, but they're expensive too. On top of that, what happens if you can't regain control? The autopilot happily flies your plane until it runs out of fuel/battery, and crashes into God knows what...