Not to downplay the importance of it, but I wonder if utilitarianism (eg mitigating climate change) should be the impetus for animal welfare. To this mind, the pure and simple recognition that animals, including insects, are sentient creatures, capable of feeling pain or suffering and with the natural instinct to live and thrive, just as us humans, even if the former are not as intelligent, should be enough.
Yes, pests need to be exterminated and animals encroaching on farmland need to be dealt with, etc etc. But perhaps what we require first and foremost is a tectonic shift in mindset: the understanding that all life forms share the same planet, and nothing exists in nature that is not of necessity. Hence, it behoves us as the one species capable of causing a sea change around us, to be more compassionate, and more creative in developing ways to coexist with other species. And whilst it is true that ultimately life depends on life, and therefore some 'loss' is also 'corollary' (such as in the case of pests), our driving principle ought to be 'to do the absolute minimal harm' to other living things and the environment at large... rather than 'we will because we can'.
Still, better late than never. The proposals to enhance animal welfare in Hong Kong have been a long time coming. It is my small but fervent hope they will also spark larger thinking, mirroring back to us our attitudes towards other ‘categories’ of life, viewed in terms of age, socio-economic background, race, faith tradition… whatever. (A couple of commenters here have already asked, what about protection for the elderly, those in ‘caged homes’, and other ‘disadvantaged’ groups? Kudos.) Indeed, seeing universality whilst also recognising and accommodating diversity, both in the biosphere and the human realm, is a very fine art the importance of which can never be overestimated.
PS For the record, I am a former meat-lover who has been a vegetarian for the greater part of my life to date. Not a rah-rah animal rights activist, but I also make every effort to patronise, as much as possible, vegan/vegetarian/cruelty-free products. After all, we are all part of the violence towards animals (and the environment) through the chain of supply-and-demand.