OpenSuSE

As an openSUSE user, I want to also point out that you can upgrade from Leap -> Tumbleweed really easily, so I highly recommend starting with Leap and upgrading to Tumbleweed later once you get a feel for the system and want something a little more exciting and up-to-date.

That said, I don't recommend openSUSE for a new user unless you're in Europe, because there just isn't a huge userbase or single community I can point at. Support is high quality, when you can find it, but quite a bit less plentiful vs Fedora. That said, SUSE is huge in Europe, so you could probably find a lot more non-English language support.

So if you're sold on an RPM distro, I recommend Fedora, not because openSUSE is bad, but purely based on community support. That said, my primary recommendation is Linux Mint due to community size and proximity to Debian (which also has a huge community).

OpenSUSE defaults to KDE Plasma.

That's not really true, it asks you in the installer which one you want. However, most openSUSE users seem to recommend KDE, so you'll probably get the best help with that desktop (and it's what I use, now that Wayland support is pretty good).

At the end of the day, I recommend

I differ a bit. Here's what I recommend:

1. Linux Mint
2. Fedora
3. Debian
4. openSUSE Leap -> Tumbleweed (start w/ Leap, upgrade to Tumbleweed later)
5. Pop!_OS

I use openSUSE, but put it lower due to limited community support. It's the perfect distro for me, and I love the different spins it has. I currently use Leap for servers and Tumbleweed for desktop/laptop, and I plan to transition to microOS for servers.

Arch

I don't see Arch as a meme, I think it's a fine distro and I used it for several years. However, I don't think it should be anyone's first distro, or even second, not because it's hard or complicated (it's remarkably simple), but because it doesn't really have any guardrails, so whether you have a good or bad experience with it depends more on you than the distro itself.

That said, don't use Manjaro, it's not "easier Arch" or "safer Arch," in fact I think it has way more problems than Arch does. If you want an easy install option, I recommend using something else first. If you are familiar with Arch, then use something like EndeavorOS so you don't need to do all the setup, but as a first time user, I recommend using Arch's official install process instead.