1024 is absurdly low for a modern platform. This is just one of those traps that Linux and the other surviving unix-like operating systems leave laying around for their users to fall into. It is possible to exhaust all memory by opening a huge number of files, but there are lots of ways to exhaust all memory, so that's not a good reason. On a modern system, which typically have a minimum of 8GiB main memory and usually much more, you can safely set it to a million or whatever.
The only reason you'd want 1024 as a limit is if you intend to start a process that might have been naively written to use `select` without checking the limits.
Someone elsewhere in the comments pointed out that 1024 is just the glibc limit, the syscall on at least Linux and possibly FreeBSD allows expanding it
any good guides on how to set this up? not tutorials on ulimit, there's a man page, but I note 1024 is one of those very square numbers, and wonder if they need to be power of two, or correlated to block size or blah blah.
in this day and age, shouldn't these numbers be a function of RAM size or cpu count? yes this means that the defaults on my computer might be less than on yours, but I think that is a small price to pay for the more appropriate setting for the majority of users.
1024 on my workstation. seems low.