Hm, well, that has not been my experience with RetroPie, I've had none of the issues you mention. Everything just worked as expected on the first try. Very simple, very plug-n-play. Was this an older version you tried? But yeah, I understand that it sucks if you have to mess with stuff like that to even get going.
The launch menu is there so you can change stuff like which emulator core you want to use for the game you're launching. You can't do that with Recalbox, then...? Usually it's not necessary, but sometimes you can get much greater results if you experiment with different cores for certain games. Either way, RetroPie has the recommended cores set by default, and you can very easily disable that menu if you never want to mess with it. In general, unless you have some specific odd issue (like you had), RetroPie is just as simple and plug-n-play as Recalbox from what I can see. You don't have to know anything about Linux, you never have to touch the terminal (but if you do want to it's very powerful, of course), etc. The only "hard" part is that you have to burn an image onto your SD card I guess, you can't just drag and drop a bunch of files.
I'm sure Recalbox is great as well, I just can't see what it offers me that RetroPie doesn't. Just seems like a more limiting and less flexible version of the same thing to me.