LMAO. No, the artist today no longer has to kill the rabbit. Do a quick google search and find all kinds of readily available bottles of rabbit glue, fish glue and hide glue for about $10USD. They're used by artists for sizing canvas, gold leafing, by luthiers for assembling guitars, violins, etc. The prestigious Taylor Guitar Company uses hide glue for their instruments because it dries strong and hard, but can be softened with heat and steam to disassemble for repairs and then put back together. If you want to try making your own (I did) go to the pet store and buy one of the raw-hide chewy toys and boil it in a pot of water until you get a creamy beige slurry. That's hide glue. Apply it with a brush. It will stick your fingers and other things together.
Thing is, there are folks who consider themselves purists in whatever their chosen thing is, but they inexplicably pick and choose what they want to be purist about.
I knew a woman in Puget Sound who made her own oil paints- she felt it helped her as an artist to follow in the footsteps of the Masters yada-yada- but, again, she inexplicably forgot to do the other crap the Masters did- making and repairing brushes, grinding pigments- some of them toxic- purifying their oils from walnuts or linseed- and, yes, making rabbit glue.
From my very favorite author, ever, Sir Terry Pratchett, sums up the idea of "purists and enthusists" in another way:
"And the major was, indeed, not a fool, even though he looked
like one. He was idealistic, and thought of his men as 'jolly good
chaps' despite the occasional evidence to the contrary, and on
the whole did the best he could with the moderate intelligence at
his disposal. When he was a boy he'd read books about great
military campaigns, and visited the museums and looked with
patriotic pride at the paintings of famous cavalry charges, last
stands and glorious victories. It had come as rather a shock,
when he later began to participate in some of these, to find that
the painters had unaccountably left out the intestines. Perhaps
they just weren't very good at them."