stable coins are independent and mainly have a 1 usd value like a dollar . they dont depend on how crypto works because no matter how crypto moves , stable coins are still stable coins and there is an accurate amount to expect on them .
@op . all of the assets that you said on your post are i think stable . just choose if where you are comfortable with . if you love something online then go for usd but if you need something that you can see and feel then go for offline assets like gold and usd ( local currencies )