My kids use Linux. They are 5 and 7. They do just fine. They are “normal”… as in just beginner users.
The 5 year old only cares where Steam is, and where the games are in the menu.
The 7 year old is a master at it all already. He’s installing Minecraft mods all the time… downloading, unzipping the mods… running java -jar XYZ from the terminal… yeah I had to show him the first time, but TBH, I didn’t show it all to him. He read up on how it works and watched YouTube videos on it.
It’s all about what you’re used to and if you’re actually interested in learning the bits. Normal is what? Someone who treats the computer as an appliance? Yeah… with those users as long as the machine actually works… they don’t care what the underlying OS is… OSX? Windows 11? some Linux distro? It’s all the same to them. The computer is a magic machine that does things and they have no clue how or why.
It’s amazing how quickly they get it.