"Why cant we have just AVI and be done with it."
Because AVI would be a terrible standard - and would stifle improvement.
Same is true of any format.
And who would be the body to agree it and to police it? - It's a free market - that's why we get improvements and enhancements - with competition.
All you and your mates need to do is to agree between you what to use - then you won't have that problem.