Backup is only part of what we are talking about, and that part is of course not too demanding, unless you are going to explain to someone how those 12 or 24 words have a backup function at all - because 99% of people think that words are just words, and yet it is a visual presentation of something much more complex.

On the other hand, try to put yourself in the position of someone who installed a wallet, had a backup and now wants to learn how to make transactions. You have to explain to that person what a public address is, what a change address is, what clipboard malware is, what a fee is and how to set it up correctly, what RBF is and how to use it in case the transaction gets stuck... In addition, if the wallet is not localized in a language that the person understands, you only have one more problem on top of everything else.

I don't see how using Bitcoin can be simpler than it is now, but let's be honest, it's not for anyone no matter how hard we try to make it.