That's sorta like the 3 patties of meat on a burger crew. WHY?
The problem with that is a lot of the fruits we are talking about on the country fruit wine forum have much more flavor per pound than grapes. The water content of strawberries, blackberries, raspberries and blueberries is so much lower than the average grape.
The number of patties you put on your burger depends upon the size of the burger patties and the size of the bun, too much of either and your burger is either a bread sandwich with a little meat tossed in, or a meat sandwich with a little bread to hold it together. But in the end, it's a personal choice, and each persons right to choose.
The same is true of wine folks, it's about balance. I'm not going to get into a big disagreement about what fruits have more flavor per pound or how much water is the "right" amount for any fruit or wine, be it grape or some other fruit. We use barrels to concentrate our flavors (and to oak of course).
Consider this, the best grape wines, generally speaking, come from vines which are stressed and produce little bitty grapes, full of concentrated flavors and much less water. The yield is lower per acre, yes, and the wine more expensive. It's a significant factor in the quality of many of the wines we've been seeing from the droughted California vines over recent years (and some good winemakers too!!).
Everyone's taste is different, and you should experiment and see what you like best in terms of fruit to water ratio. Sure, see what others like if you haven't done it yet, try others wines if you have the opportunity and find out how they do it. After that, be the winemaker and make what you want, flavorful as you want, sweet as you want, oaky as you want, whatever
you want.
For me, I choose to pursue concentration, I'm doing a blueberry with no water added, 10 gallons of blueberries in the freezer. I might not get 5 gallons of wine, but it doesn't matter to me, because that's what I want to do.