Of course, the answer is they are a good business
Investment in 'events' is profitable ... if something is profitable, it attracts investment and grows. That is the way the free enterprise capitalist system works. According to many purists, because something is profitable, then it must be good. According to the evidence I have seen, an awful lot of profitable activity is not good, in fact much profitable activitiy is doing serious socal and environmental damage.
EVENTS as a REWARD
TPB observation: During my working life I have attended many events, some of which were quite valuable, but not really that many. Mostly the events were an excuse for a social outing, and in the case of many people with rather boring jobs, something of a reward for doing their boring work well. There is nothing wrong with giving a reward to staff, but it should be understood that this is what is going on.
TPB observation: Some professional conferences are very important. They enable leaders in the field to share their experience with others, and with this knowledge sharing the profession is improved, in some cases very significantly.
Unfortunately, while a good many of the participants in professional conferences do get to upgrade their knowledge and skills, here are many that have substantial cost and the added value is insignificant. For them the net value add is negative. The big winners in all major conferences are the organizers and the travel and hospitality industry ... and they have every incentive to keep the conferences going year after year!