1. You're using latest upstream, after it passed through the archlinux-testing repository. This means you won't have to install software from somewhere else just because the repos are outdated. (nighly builds of software are different)
2. Sometimes you have to sys-upgrade to install/fix something, and you don't have much say in when that happens. Typically you need to preemptively do this about once a week to not potentially get interrupted by manual intervention at a bad time. Yes, you will need to do manual intervention, but you won't spend much time on it. It's far less work than getting up-to-date software running on your debian stable.
Arch will give you small issues every now and then, but it gives you the tolls to fix them and makes it easy to do things that are much more difficult on other distros.
I like what they are trying to do but it just did not work for me.
Arch is hard to figure out too with the wiki based docs but at least that’s advertised as unfriendly.
Don’t do this to yourself! Debian is not going to give you bleeding edge. But there are plenty of distros that can. Despite being a meme, Arch Linux is one of the best distros available, and has been for years. Node, golang, are usually updated within hours of upstream, while the core system remains stable. If you’re looking for something more modern, Solus has been gaining popularity and also has relatively up to date packages. Debian is great for servers.