Obviously liberalism played a big role in shaping modern society and our conception of rights and responsibilities, and there is merit to using that concept when we have to negotiate our current legal framework. There are notable ways in which social movements have used the language of rights to mobilize for change and so on. But there are also major problems with this approach.
First, it assumes that the framework of rights addresses human freedom, social justice and so on, and it actually doesn't. Instead it abstracts us as somehow all having certain rights when the truth is that we all face different social realities. Having the "right" to buy food is irrelevant if I can't afford it. And having the "right" to free speech means nothing if I can't access education, or if I can't speak up because I have always been told to be quiet.
Second, it ignores power relations more broadly. Anytime we debate a question with social implications, I think we should ask about how power operates in that context. Not power as a disembodied thing. Everyday social situations or encounters are always marked by power, whether we see it or not. For example, wealth, access to education, access to markers of a fulfilling life, like a decent job, or an emotional support system, etc.
People may be driven to suicide because of a range of factors, but instead of looking at it abstractly, we may want to ask, what are certain factors that contribute to a good quality of life, and who does not have access to such a good quality of life. If we do that, then we have to talk about economic justice, exploitation, and certain other social problems. Then our conversation about suicide becomes a responsible conversation that actually grounds the problem in the real world.
Following from that, if we were to say that we need to address social problems (something let's say that as a society, we are all collectively accountable for) to prevent suicide, then we have ourselves a different question to debate altogether. I would much rather debate that question. Why? Because I think it is grounded in social realities, not decontextualized and abstracted as if it is a mathematical problem that can be solved by logic alone. I think when we are asked such questions, it is important to complicate the terms of the debate a bit and not take it at face value. In fact, challenging the terms of the debate is in itself an important analytical contribution to any debate.
Suicide involves death and is obviously tragic. But other forms of death are also tragic. It's tragic die from preventable illnesses, for example. But why is it that terms like cowardice are used to talk about suicide? Why does suicide demand the kind of attention that it does, and why does it horrify or fascinate people in the way that it does? Could it be that it potentially signifies the extreme end of individual freedom.. that someone could cut themselves off from society? I don't really know. But I do know that the individualism that is inherently produced through the phrase "right to suicide" needs to be challenged if we are going to try to understand why it happens, or even better, if we are interested in preventing it.
As my homeboy Marx said philosophers have interpreted the world, but the point is to change it.
* and by liberal, I mean the technical philophical term, and I am not (mis)using it to mean "leftist." Liberalism as a philosophy of individualism and individual self-determination, etc.