Championship titles are apart of almost every athletic sport. Championships in non-scripted competitions are typically won through skill. In Pro-wrestling, championships work in a slight different fashion and there are a few misconceptions of it.
People commonly make the mistake of calling championship titles "belts." The proper term is simply a title because it signifies that the pro-wrestler is a champion.
Championships are designated by several factors such as weight, height, gender, wrestling style, and other qualifications such as the audiences view on the title's value.
Bookers decide which pro-wrestlers deserve championship titles in accordance with what is most profitable for the company and high interest with fans. Pro-wrestlers as a result from being champions become famous, gain a higher pay raise, sell merch., have a higher chance of being used in a storyline, and noticed by other promotions.
Now one would ask "If Pro-wrestling is scripted then what then is the point of being champion?" which is a great question. The purpose behind giving pro-wrestlers championships is a sign that the company and fans favor him or her. A pro-wrestler becomes champion when he or she demonstrates outstanding qualities in terms of work ethic, in-ring performance, ring psychology, and so on.
In summary, championship titles aren't just shiny belts that pro-wrestlers wear around their waists. They are the mark of a pro-wrestler who won the audience's favor through his or her skills to entertain and other factors.