Pretty much all the guidelines about swap partitions out there reference old allocator behaviour from way over a decade ago - where you'd indeed typically run into weird issues without having a swap partition, even if you had enough RAM.

Short (and inaccurate) summary was that it'd try to use some swap even if it didn't need it yet, which made sense in the world of enough memory being too expensive, and got fixed at the cost of making the allocator way more complicated when we started having enough memory in most cases.

Nowadays typically you don't need swap unless you work on a product with some constraints, in which case you'd hand tune low memory performance anyway. Just don't buy anything with less than 32GB, and you should be good.

plenty of footguns in that general advice, local in memory storage services with default config, etc