EndeavourOS is a terminal-centic distro (it isn't trying to be very user friendly but just easy to install and with some very important stuff included). Garuda has some modern performance improvements (preload, Zen kernel etc) and generally a lot of stuff preinstalled. Manjaro tries to be a general good easy to use desktop distro without Garuda's optimization stuff but it's quite bad at it because of poor management of the project
It really depends on your hardware. I don't think you'll have any boosts. The "Gaming Edition" can even be worse than average because of the amount of purely aesthetic whistles preinstalled. I think it's more about performance in regular tasks on modern machines. Preload will greatly improve app loading times there. For gaming just use a rolling release distro to get newest drivers. I also wouldn't recommend running GNOME because it seems to decrease gaming performance here and there. Other than that it doesn't really matter and in case something does you can install/tweak it on other distros as well
You're welcome but I'm not much of a specialist so half of my answers might probably be wrong lol. Considering the fact that I decided to answer your questions anyway, thanking me might not be considered very fair
I've been using it daily for about a year on my primary desktop gaming pc without any issues. I love it.
As for performance, I vaguely remember phoronix doing a benchmark comparison of a few distros and in some tests it was marginally better (cannot find it now though...). For the most part though I'd say it's not as much about potential performance gains as it is ease of use for gaming. So many useful tweaks and useful programs "out-of-the-box".
Garuda goes for the looks and the gamers I would say. I've tried Garuda before and it was nice that it was possible to roll-back installation versions but on my ancient test hardware it didn't go too well, also not with rolling back.
Manjaro got quite some bad press in the past for good reasons.
Here you can compare a few descriptions for all of them :
Endeavour is Arch with an easy to use graphical installer and a few changed defaults. IMHO it should be merged into Arch itself as an installer option, but I guess making it too easy to install is against the project philosophy... It's basically Arch aside from those details.
Manjaro uses the Arch packages so it's also rolling (not sure what the other comment means saying it's not) but curates everything heavily. It has a "stable" package branch which doesn't exist on Arch, where packages enter after testing and a two week delay on average (probably where the rolling confusion originates from; it's still rolling, just later).
It comes with a LTS kernel by default and all kinds of other safety and helpers. It has its own package manager with a GUI, a driver detection and installer, a kernel version manager, automatic OS snapshots after every upgrade so you can restore if something breaks etc. (I've never had to use the restore but it's nice knowing it's there I guess.)
It's quite stable and nice (I've been using it as my main desktop driver for work and gaming for the last 4 years) but you have to stick to its recommended features for it to remain stable. There are people who switch to the non-stable branches, or use non-LTS kernels or do other changes and it breaks and they end up upset.
There are all kinds of rumors circulating about it because of that, saying you can't use AUR packages on it (you can) or that it's buggy, "badly managed" etc. From my own experience it's a perfectly nice distro provided you want to get the distro out of the way and focus on doing other things, but still take advantage of rolling packages. If you want to experiment and tinker with the OS you're better off on Arch or installing through Endeavour.
Garuda is somewhere in the middle, has an installer and nice defaults like Endeavour, has helper GUIs like Manjaro and uses Manjaro's GUI package manager, but doesn't take things as far as Manjaro (with the stable branch and kernel and curation etc.) Also has a gamer-oriented thing going with a cool desktop theme and a gaming package manager GUI.
I had problems with Manjaro, would not recommend it, and now use EndeavourOS.
That said, you did a fantastic write-up here. Really well done.
I don’t need EOS and Arch to merge. I would be happy if Arch would just include yay or paru in the main repos so you could use the AUR out of the box.
The problems with Manjaro are not just people using non-stable branches or even project governance ( though that had unfortunate moments ). The biggest issues I had were the disagreements that Manjaro had with the AUR due to missing or outdated packages. As you point out, these packages are merely delayed. However, the decisions made about system state today can carry forward into the future and are not always unwound once the core packages finally update. I had issues with pamac as well where it would install old packages instead of new ones unless I cleared the cache all the time. Maybe that was somehow my fault. I use plain old yay and paru now with the occasional pacseek for good measure.
Manjaro is still a good looking OS though. I think most people prefer the green to the purple in EOS. Lots of people love the look of Garuda but, for me, it is too much.
Again, really nice write-up. I hope Manjaro continues to serve you well.
I don't think anybody wants to take responsibility for actually endorsing the use of AUR with their distro. That's why helpers are not installed by default on Arch, that's why support is disabled by default on Manjaro even though the pamac helper itself is installed, and so on.
AUR is a wildcard. It's anybody's guess whether packages will work at any given time and whether they'll work after your next system upgrade, and if course they're have been all kinds of issues, overlapping package names being just one example.
I don't think "AUR compatibility" is something that any Arch-based distro aims for, certainly not one of the primary goals anyway.