Our sacred scrolls must be written on parchment, if they are to be kosher - fit for ritual use. Parchment can mean many things, but in this context it means animal skin.
Parchment for sifrei kodesh, sacred scrolls, has to come from a kosher species of animal, but the animal does not have to have been dispatched by ritual slaughter. The kosher meat industry has its ethical problems, but the non-kosher meat industry, arguably even more so. To be kosher meat, an animal has to be reasonbly healthy; to be a kosher mezuzah, the animal could have been most horribly maltreated.
But a mezuzah reminds me that I am living a Jewish life, and a big part of a Jewish life is respect for all life. It troubles me that my mezuzah - worse, my sefer Torah - should be tainted with such suffering.
In the world of kosher meat, these sentiments take the form of animals raised humanely by people who care, slaughtered carefully by people who care, sold to people who care. All these exist. The idea of humane treatment of animals and kosher meat has taken root.
The idea of humane treatment of animals and sacred scrolls has not.
We have the humanely-raised animals. We have the humanely-slaughtered animals - we can get both of these from the non-kosher world as well as the kosher world. As far as I know, we don't have anyone who knows how to make kosher parchment who would be bothered to use only these skins. So we'd need that - or at least, someone who wouldn't dismiss the idea as goyische nonsense. Then maybe we could make mezuzot - perhaps megillot and Torahs, with enough skins - that hadn't suffered. If we had someone who knew how to make tefillin cases, we could make tefillin also.
I fear that's a long way off, but I think I'm not the only one who would like it. I would like it better than giving in and just using alternatives. Saying "The meat industry is messed-up, therefore I will change the Torah and use parchment alternatives" is accepting the messed-up-ness of the meat industry. I would rather say "I will tackle the messed-up-ness of the meat industry rather than change the Torah because of it."