I'm a bit confused. For all the description of different convoluted processes below, why not simply handle backup with something even simpler like Backblaz, Spi

I'm a bit confused. For all the description of different convoluted processes below, why not simply handle backup with something even simpler like Backblaz, SpiderOak or maybe sync.com? Seems a lot simpler than the Restic, Rclone and other methods described here.