Changing offset changes the stress point/angle on the wheel bearings
Wears them out faster
Also looks kinds off with huge wheels way out the guards ( off-road style)
It also changes alot more than most people think. If you put the wrong offset wheels on your car and a tire blows out at the front your car will violently pull to that side. It can also wear out your tires more quickily. It's more important on a FWD car rather than a RWD but it's all ways better to use the proper off set if possible.
At the end of the day it's not going to make much difference you'll end up with the same result. With a spacer you can use the wheel on another car if need be. But I wouldn't trust them myself