The reasons you mentioned for gathering strong evidence not being possible (or being very difficult) apply to some extent to efforts increasing human welfare, but humans have probably still made progress on increasing human welfare over the past 200 years or so? Can one be confident similar progress cannot be extended to non-humans?
I agree research can backfire. However, at least historically, doing research on the sentience of animals, and on how to increase their welfare has mostly been beneficial for the target animals?
The reasons you mentioned for gathering strong evidence not being possible (or being very difficult) apply to some extent to efforts increasing human welfare, but humans have probably still made progress on increasing human welfare over the past 200 years or so? Can one be confident similar progress cannot be extended to non-humans?
I agree research can backfire. However, at least historically, doing research on the sentience of animals, and on how to increase their welfare has mostly been beneficial for the target animals?