Although you could out-take some failures, you could also out-take the success.
The bottom line is that they were able to achieve the desired capabilities. Now that capability is available to everyone.
And they have gotten much better since then.
This decade, robots have successfully unbolted from the factory floor; to safely walk, fly, swim, drive and snake through pipes all around us, in many different forms.
Next decade, great masses of robots will be doing so for work, rather than testing.
Once the basic platforms are developed with human-like mobility, strength, dexterity and sensitivity, it is just a new software app for it to take over the next job - Chef, bartender, maid, landscaper, mechanic, surgeon, nurse, masseuse, security guard - whatever.
There is a threshold coming where a general purpose robot can replace an unskilled person. After that, the robots will get much better, more quickly than humans could. Specialized robots are already replacing humans at an increasing rate.
The robots of today are like the Wright Flyer was to aviation. It is going to get interesting very quickly.