Yes, the kernel has great support for ARM. Distros that need to package up the kernel, tweak the bootloader, deal with peripherals, etc.... less so on great support. ARM is a bit of the wild west with SoCs defining all kinds of esoteric and exotic hardware configs managed by the kernel's device tree infrastructure instead of a typical BIOS. If you're dealing with server workloads it matters much less (and they probably support UEFI) so stick with a distro that has good support (Ubuntu, Fedora, etc.). If you're dealing with ARM hardware directly like little SBC boards, start getting comfortable rolling your own device tree, bootloader config, etc. as you're probably going to need it. In all cases though the stock mainline kernel is fine to use.