I think the concern was areas that were way too easy because you out levelled them, either doing things in an unexpected order or being a completionist and doing all the side quests, etc.
Level scaling doesn't have to be implemented so that it drops opponents below the level they were intended to be.
But that's the point... areas
should be easier when you outlevel them. That's the boon, that's your choice; making late game easier by taking the hard way early on.
Smart encounter design would make late game challenging even for a completionist (without any level scaling). People who find it too hard? That's what difficulty levels are for; you have the option to reduce difficulty.
