The answer to the question is a bit obvious, it would remain in your wallet, ofcourse, unless, there are other people who knows about private infos of your wallet in order for them to take over of your holdings. Your holdings won't vanish just because the wallet is no longer active, as far as I know. So basically it does depend to the person if he would let other people know about his investments in crypto if ever he would die someday just to be prepared and for investments to not be wasted.
Basically, if the owner dies and his wallet was left inactive, the supply of circulating crypto will decreased. Unless he trusted it to someone else and continue using cryptocurrency as his heir, which is better so someone can benefit from the earned crypto than letting it to put to waste and become inactive forever.