If you ever tried learning to edit music using reel to reel tape, a pencil, razor blade, and sticky tape...
then you'll understand the value of paying a professional..

But for getting on 2 decades or more, software displaying visual wave forms and employing cut and paste
has made editing accessible for the masses...

But you still need a good trained experienced accurate ear for timing and cross fading...

Selecting and installing the free software is the easy part...