Because what you described is an unbearably complex, and highly unreliable solution. There is no way your home storage is more reliable than a geography-duplicated cloud center with 6 nines (or more) of data reliability.
If you love spending hours a day twiddling with linux configs, knock yourself out, but my time is worth more and the every arrow of opportunity cost points toward an integrated cloud ecosystem.
I prefer to save data in the cloud, and not "on the computer... in my house..." as the hank hill meme goes, because that hardware is painfully fragile.