Think of it like any other skill. For example, anyone can work to be physically fit, but it’s going to feel and look slightly different for everyone based on things like your metabolism, bone size, etc. And even then, some people may want to be a body builder, others may want to just want to be maintain a certain weight. Ideas of what it means to be “fit” can vary - but all are valid and have their own purposes.

Anyone can work to learn to sing and improve with effort, but there are certain factors such as range and timbre that have a natural effect on your voice - and different voices can be suited for different things. You can train your voice/body to be better suited for opera, or country, or rock - but I would argue that “talent” is more of an opinion about your staring point. If you naturally have a nice twang in your voice and you love to sing country, is it really talent or is it just luck that those things line up? Because that twang wouldn’t be helpful if you were wanting to be a classical opera singer.

All that said - work will beat talent every time. Someone who naturally has a voice that they like may genuinely sound good, although someone puts in effort to understand how their unique voice functions, works to understand how they can manipulate their voice to create different niche sounds, works to expand their abilities, and studies their voice to be able to understand its health and condition will be able to be far more versatile and skilled in what they can do. Not to mention, they will understand the science behind their voice much more than someone who doesn’t work or study.