People argue that you only get what you pay for, implying that free software is somehow defective. However, that couldn't be further from the truth. The reality is that companies that produce paid-for programs have serious concerns about the longevity of their companies with their current business models.
Comparing their own limited teams of programmers who are doing it for the money and know in the back of their minds that they will never be recognised for their work, they are up against the rest of the world, a vast army of programmers who can discuss openly any problems they might have encountered and how best to solve them, programmers who know that their work can be inspected by anybody and therefore they should make a good job if it, programmers who are doing it for the love of it.
Blender is one of the image processing programs that I use occasionally so I wouldn't call myself an expert on the details of its workings, however, even though I probably only use a tiny fraction of its capabilities, it does produce good results and being free, I'm not paying for things I will probably never use.