I don't have nearly that much trouble with Arch anymore. You know when you get 3GB of updates to watch out, but the general trend in recent years has been positive - more issues have been fixed than made. My most recent one being that Dolphin can't properly save edited desktop files anymore.
There is a testing repo for a reason. If Arch had more adoption, the model can and would work, because you would eventually get enough powerusers in testing to live that life of worry the next update kills your desktop. More people would mean more packages are held for testing, and more people would mean more of the AUR packages would be pulled into community. The only potentially defective design is releasing known regressively bugged software to release channels just because the bugs don't completely break the system.
ChromeOS can sound impressive until you wonder when the last time OpenRC + the kernel broke, especially when you have Google engineers auditing and patching the Gentoo kernel to insure compatibility on their devices. By comparison the last issue I had with systemd was.... never, really. I even made it through the switch with a fully working system, I just had a lot of missing services I had to reenable.
When Arch breaks, its always either A. the graphics stack, B. Xorg and its ilk, or C. bootloader. Its super rare for a kernel to be pushed upstream that regresses wifi (unless your broadcom out of tree driver breaks), or audio, or peripheral connectivity (usb, bluetooth). Its super common that major upgrades to X or Mesa or libGL can either kill acceleration or your entire desktop period. And having switched to directly efistub loading my kernel, I haven't had bootloader problems ever. And systemd has built in gummiboot now.