Academia is generally more amenable to long-term fundamental research.
Research in academia can be made for the profit of all (often without patents) rather than for a particular group of owners of a company. I feel that I am working for humanity as a whole and this is very rewarding.
A university professor contributes greatly to training the next generation of researchers, and this is also very important for the progress of future research.
I don't consider that I need a better salary to increase my level of happiness. I already have all the gadgets I need.
A university professor is basically their own boss. I can choose the topics of investigation that I want (although this is also true in some industrial research labs I could name, it is not generally the case in industry).
I get a very high leverage through my collaboration with a large group of graduate students, something that is not always easy to get in industry.