Yep. Package management is the core of a (Linux) software distribution.

I thought the current process was just to herpderp it and put everything into a container.

I hope that fad dies. It assumes all the world is x86-64 Linux. Maybe you get a few who acknowledge the raspberry pi. However there is a whole world of new other processors, *BSD, and others that the fad makes difficult to use.

Linux package management is already fragmented, the last thing we should do is add programming languages package management to it.

Nobody that currently exists - at least to my knowledge. This is a hard, mostly thankless problem. Distros solved a similar problem, but they have different motivations and so didn't fully solve everything. Languages like rust have a partial solution, but they don't play well with other languages and the full complexity that can result.