WTF! This is such a non-Apple type of recommendation. Smells like feedback coming from MS back in the days.
Actually that's exactly the Apple kind of recommendation. Whenever I've had such an issue (e.g. with battery) and contacted Apple Support chat, that's the same thing they'd tell me, to restore and hope for the best.
But the thing is, in my case, I've already done a clean install of iOS 14 on my 11 Pro and battery is a potato. So what then??