There was a time when device support in a Unix meant being literally built into the kernel. Then modules became a thing. Linux has thousands of modules repres

There was a time when device support in a Unix meant being literally built into the kernel. Then modules became a thing. Linux has thousands of modules representing device drivers, iptables targets, crypto processing, and others. So while the codebase may become larger with the additional devices supported, this doesn't have to impact your running kernel at all. Modules that represent hardware not installed on your system aren't typically loaded and therefore don't occupy RAM. You can also blacklist modules, in the event something's loading where it shouldn't and you don't want it in RAM. That being said you can do an `lsmod` and look at the modules actually loaded. If some are there that represent things you'll never use (like QNX partition support), blacklisting them may save you some KBs of RAM and lower your kernel's attack surface. QEMU's floppy disk hardware support was impacted by a security vulnerability not too long ago, and I've had the `floppy` module blacklisted for a long time on my VMs. If you are running Linux on a purely static system that won't change hardware over its life (including things like USB devices), you can then compile a kernel with all modules "built-in" and disable module loading entirely.