The last time I seriously tried to use Ubuntu was probably 8-10 years ago and I ran into a lot of trouble trying to get up to date graphics drivers via PPAs. I also remember being tired of having to go find a random PPA for every piece of software I wanted. Most of the time I would just find some random blog that provided a "PPA for up-to-date package X" and ultimately felt like what I was doing wasn't really any better than downloading random MSIs like you would on Windows.
With Arch though you get the AUR which quite literally has every piece of software you could ever want and is at least managed and maintained in a central place so you're not just adding random PPAs for everything.
I don't think the AUR is necessarily more secure but in general the nature of how the AUR works does perhaps give some slight advantage. The suggested approach to the AUR is to download and inspect the PKGBUILD so you know how/what the package is doing opposed to a PPA typically being a precompiled binary. AUR helpers will also typically show recent comments, etc. so if a package was compromised or had issues you'd probably know as you're pulling it down.
Really though the AUR just tends to be more convenient and complete than finding random PPAs in my experience.
You're supposed to separately manage the software you care about. e.g. there's a nodejs for people who don't exploit it in their daily use except as dependencies to other software, but if you use it regularly you should manage your own nodejs binaries.
I spend more time just trying to have up-to-date software on that Ubuntu installation than I spend time configuring anything about the arch installation. Granted, sometimes you need to edit some files after an update (oh device names changed again in pulseaudio so your volume hotkeys need to be fixed!), but that's usually a matter of seconds because I already know how everything fits together. When a package is totally broken for some reason, I just downgrade it.
Meanwhile on Ubuntu your only option for getting up to date versions of Jameica/Hibiscus, pretty much any mapping software that OSM contributors/users would want to use, and a bucket list of other productivity software that tends to be useless if outdated, is to compile from source (don't forget to fix incompatibilities with Ubuntu's libraries!) or manual downloads. Oh I forgot to mention Subsurface and TurtleSport. Don't get me started about those. Bonus points for Ubuntu not having disabled the built-in version checks in a lot of software (it's usually just a compile time options or command line argument!), so it nags users that they're running outdated software when there's no way to upgrade!
At this point I'm convinced the only noteworthy software that Ubuntu manages to have acceptably recent versions of is Firefox. If all you want to do is browse web, Ubuntu might be less work.
I'm not surprised Ubuntu is trying to move to snap packages. That's their last ditch attempt at getting their house in order.
Arch will always at least have an automatically installing AUR package for you with a version that isn't from 2018.