I am now anticipating some form of an existential crisis around whether animals that can talk via a specific language are any less entitled to rights than other humans.
The US literally passed a law allowing itself to invade The Hague if necessary to free any US service member brought before the International Court of Justice. Even the signatories of the UN human rights conventions could simply refuse to cooperate and experience no meaningful consequences. International laws are just treaties and treaties can be cancelled or revoked. Human rights are no more reliable than company mission statements.
Not to mention that even on a national level laws only exist as limitations the state imposes on itself (or to chisel away at limitations it imposed on itself before). This is why it took the civil rights protests and literal terrorism to arrive at universal suffrage and civil rights for women and Black people. Of course this only works if the government would rather change its laws than escalate protests to a civil war and which one your government chooses might surprise you.
And yep, everybody's just a monkey with or without a stick.
Of course if for some reason the domestic meat industry collapsed and people relied on imported meat there would be an incentive for praising lab-grown meat or veganism because it would benefit the domestic companies but that's more or less the inverse of what's happening in the US.
Aren't all animals sentient? And what is the difference between "truly sentient" and "sentient"?
That said, rights don't happen through scientific discovery but through reform or revolution. There are strong economic incentives to keep animal rights minimal and there is only very weak political will to change that. It also doesn't help that in the US there are strong religious doctrines that oppose the notion of animals deserving rights at all.
It's worth mentioning that there are indeed jurisdictions (not sure about the US) where animal cruelty laws are actually framed as animal rights (usually with some limitations, e.g. only considering vertebrates) rather than as protection of private property but even they usually don't include a right to life or bodily integrity and are flexible about what constitutes cruelty and what can be done to reduce it.
How far are you willing to go with this? Is a roundworm sentient? An amoeba? A bacterium?
Wales, maybe.
I understand the feeling here, definitely wales and corporations are not of the same ontological class.
What I was trying to point out however, was that just because a jurisdiction give an entity the status of person, it doesn't mean it give to it the same extend of rights.