that's because we've understood there's a line between what is reasonable for most users to implement - cron - and what is more reasonable for the OS to implement - systemd timers.
you don't want a user who doesn't know what they're doing to accidentally brick a key OS timer (for instance, when they're setting up their own), so systemd helps to segregate while still allowing experienced users to easily stop timers.
meanwhile, for users, cron is much easier to work with...
systemd timers are not actually universal. not everyone uses systemd, some use sysvinit, openrc, etc. systemd timers are also much more difficult to set up.
cron is not "deprecated" and is still widely used industrially and locally.
Tmux is essentially an extension of the concept of running ideas in the background. Like 0xtero mentioned, you use a sort of "virtual terminal" that is persistent (unlike the jobs system you might be familiar with on your shell).
Now, some people do just use it to split the screen. The idea is it can have multiple terminals, show them, and manage them - it is thus a "multiplexer", which is where it gets its name (tmux = terminal multiplexer). If you're on a terminal-only system, this isn't that bad of a usage.
Say you're compiling a large program, like the Linux kernel, and you want to step away, maybe even close the terminal and come back later. Tmux is great for this. You can start the compile in tmux, "detach" (stop viewing it) from it, and it'll still run full-speed in the background. When you want to look at it again, or check the status, you just re-attach.
I've never been able to daily drive Nix, or for that matter stand using it in a VM. I've always hated every aspect about it. I currently use Arch, but for stability reasons am switching back to (probably, might end up going for something debian based) Fedora on my desktop. The overall structure of Nix is just... It's not meant for a normal person to daily drive, it's designed for replicability. You don't interact with it the way you would a normal OS.
That being said, a lot of people around me love Nix, and do daily drive it. I don't know how they can stand it, but they do.
I've never been able to daily drive Nix, or for that matter stand using it in a VM. I've always hated every aspect about it. I currently use Arch, but for stability reasons am switching back to (probably, might end up going for something debian based) Fedora on my desktop.
I didn't know about the Rocky legal structure. Thanks for the pointer
While oracle has definitely always been... problematic, it is refreshing to see something actually written by a real, rational person. It may just be corporate fodder, but it's good for people in this case, something very rare - just like SUSE's not-so-subtle PR statements.
Screw RH.
supposedly it's a better format. in practice it's worse, and support is so low in most applications that it's bad. but google forces what it wants, so that means when it can give you a webp, it will to encourage adoption.
there are cases where alternative file formats can really be better: matroska, for example. webp is not better, however.