hopefully animal testing alternatives keep innovating enough that they, like some renewable energy sources today, become cheaper to make use of than their incumbents

I hope so too! Unfortunately animal studies are still one of the main pillars of physiology and drug development. They were even a requirement until very recently in the US, see the rule just approved by the FDA [1].

[1]: https://public-inspection.federalregister.gov/2026-19350.pdf