Define normal. I would argue at least 75% of the US population has zero interest in learning how to install a new OS, let alone actually do so themselves.
I say this as a decades-long Linux user (who has tried to evangelize it many times).
Gamers are one of the few demographics still buying new Windows PCs. There are now so many discord servers and subreddits filled with people discussing which Linux distro to use.
Honestly for your average home consumer, there isn't much need for a Windows PC now days.
Well I can agree with that, but that's not the same thing as being incapable of doing it. Both of my parents could easily install Linux, it's infantilizing to argue that they can't fill out a user wizard and select a drive to wipe.
You don't have to know. The Calamares installer annotates your partitions and explains what will happen in natural language. If you can order a pizza online, you can install Linux.
Yeah. If ordering a pizza also regularly involves entering BIOS setup to change boot device ordering, change SATA mode from RAID to AHCI and disable secure boot, depending on your distro.
This is funny. I have an HP PC that has an option in the BIOS to "prepare for RAID" or some such. I wondered what that was, so I turned it on. I had Linux on it at the time, and nothing happened. I shrugged and just forgot about it.
Fast forward a few months later, when I gave this PC to my dad. He installed Windows on it, then started thinking the PC was somehow borked: "the installer sees the drive, installs, reboots, then it fails to boot". I was shocked, that PC worked perfectly.
Then I remembered about that setting, told him to untick the box in the BIOS, and he was off to the races.
I say this as a decades-long Linux user (who has tried to evangelize it many times).