i am going to post this as a bug since it is possible that the recipe was overlooked for balancing mechanics
((TLDR)) balance book / bookshelf crafting because due to issues with the recipe it takes roughly 1652 items plus excessive amounts of time to make a stack bookcases. below is a detailed description of the broken crafting mechanics and the severity of the issue.
I am starting this as a bug report rather than a suggestion in hopes that the game can get a little bit better in the unbalanced crafting department. as you all know jeb added leather as a required component in the book crafting recipe making an already resource intensive decoration block even more difficult to obtain. there are several critical blunders in the crafting recipe that result in a massive waste of input resources for a very small output.
before the changes, books cost 6 sugar cane. it takes 3 pieces of paper to yield 1 book and 3 books are required for a bookshelf. a bit wasteful but still doable due to the way sugar cane can be cultivated like a crop in large fields. additionally bookshelves cost 6 blocks of wood this is where it starts to break down in terms of materials required vs blocks created.
if anyone has looked at a bookshelf in real life one would notice they only use a few small pieces of wood and consist mostly of empty space. the sheer amount of wood required for the recipe is not just wasteful but we start to see a violation of the most basic concept in the laws of physics namely the law of conservation of mass and energy. where any item made must equal the sum total mass of it's component parts or return the extra mass as byproducts or at least convert the extra mass into energy. most recopies that rely on shaped crafting compensate you for excess materials by increasing the output. so now we have a difficult recipe where the materials required are in exponentially larger quantities than the physical size and quantity of the resulting bookcase.
here is where the issue comes in since sugar cane and wood are fairly easy to make and the wasteful recipe doesn't matter that much but it is time consuming to grow and cultivate the materials needed for the bookshelf. with the addition of leather to the book recipe, the recipe while not unrealistic becomes exceedingly hard to complete since it forces players to rely on a mob drop that unlike sheep which can be sheared cows must be slaughtered to collect it. while cows can be bread for easy leather collection the fact remains that cows don't always drop leather nor do they consistently drop any quantity of the item that would be a realistic quantity of hide from a animal that size. additionally this requires the slaughter of about 3 cows to one bookshelf on a good day combined with the breeding delay and amount of wheat required to breed.
so basically we have a recipe for a single blocks that requires the following
9 sugar cane
6 or more wheat to breed cows
3 pieces of leather requiring the slaughter of 3 separate cows on a good day up to 5 - 6 cows when drop rates are slow
this yields only 3 books BTW
now add to those 3 books another 6 planks and you have one whopper of a material list for just one single block
now for a stack of bookcases the total material cost is around
6*64 or 384 planks around 96 logs which is a lot of trees.
the book requirement is 3*64 or 192 books which is 192 pieces of leather that would require probably around 200-250 cows and to breed 200 - 250 cows it requires days of work and 500 wheat. and
576 sugar cane.
so in total a stack of shelves is
96 logs -384 planks
and 576 sugar cane
a total of 1652 items for net product of 64 single blocks
i am sorry but there is defiantly something wrong with this input output ratio and if the development team would revisit the issue they would see this.
an average library can contain many stacks and honestly i would probably have to switch from integers to scientific notation to count the material requirements.
but in all i think switching back to paper back books while still an excessively wasteful recipe will be a lot more friendly to the environment and stop the genocide of cattle for the time being.
((TLDR)) Balance Recipe or increase yield. the current production of the book shelf is a severely broken crafting mechanic
i would like this reopened