I've been around archery for a good while now. In the 80's and early 90's the heavy draw weight macho man archer was a thing. I always thought i was a bit crazy, eighty to one hundred pound bows, overdraws, short arrows, and LOUD bows! Its funny looking back at all that and seeing now you can get the same arrow speed out of much lower poundage than back then.
In the past few years the eighty pound bows have started to become popular again. At first, I thought here we go again... but now bows are typically easier to draw, have lots more letoff, and are more forgiving than years ago.
Do you need the extra weight? Short answer...NO. Not that long ago, deer were being killed with speeds much slower than we see today. I will also say though, increasing weight is the best way to gain fps in a big way. If you are looking for crazy knock down power, or speed I guess, why not.
One thing to mention or ask is: please don't "overbow" yourself and cause shoulder injury. Just because you can shoot 80 doesn't mean you should. Personally, the most I've shot oin a customers bow was a 104# older PSE. I wouldn't want to do that many times! -jeremy