Swap isn’t unlimited, it just delays the inevitable and makes everything slow while doing it. A 4GB swap partition isn’t going to save you if you run your 32GB computer out of memory.
It does help. It gives time for the kernel in this situation and also helps in general by allowing to defragment memory. You want to keep a small amount of swap space at all times.
Unless it's some sort of autonomous safety-related process, It's usually better for the process to die so I can just restart it.
Even if it was some sort of safety-related process that had to keep running no matter what, I would probably try to define/control the memory usage better so it wouldn't unexpectedly run orders of magnitude slower.
Anything what would request memory would just outright die, including even the most basic services.
Source: actually had a system without swap what would just die running `dnf update`. Or quietly die in a week or so if left unattended.