This is a distortion of the biblical teaching, which is, unfortunately, rampant throughout much of Christianity, particularly Calvinism. It's unfalsifiable stupidity.
It's worse than that. The way your opening sentence positions the doctrine makes the doctrine entirely meaningless. It's a tautology at best. It amounts to saying that the saved are saved and the unsaved aren't. No duh!
Again, it's worse than you imagine. Calvinism does not teach that God damns you "by not saving you", but that you were created to be damned and there was never any other option.
No "net" benefit? Try no benefit whatsoever - at least in regard to the doctrinal distortion that you are here reacting to.
The actual biblical fact is that once a person has been saved, they are saved - period. They
WILL be delivered safely to the day of redemption on pain of God forfeiting the Holy Spirit.
II Corinthians 1:21 Now He who establishes us with you in Christ and has anointed us is God, 22 who also has sealed us and given us the Spirit in our hearts as a guarantee.
Ephesians 1:13 In Him you also trusted, after you heard the word of truth, the gospel of your salvation; in whom also, having believed, you were sealed with the Holy Spirit of promise, 14 who is the guarantee of our inheritance until the redemption of the purchased possession, to the praise of His glory.
Ephesians 4:30 And do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption.
The word translated “guarantee” is ἀρραβών, an earnest, a pledge, the down payment that secures what is to come. In plain terms, God has placed His own pledge within the believer, the Holy Spirit Himself, guaranteeing the inheritance “until the redemption.” If the redemption does not occur, then the pledge fails, which means God’s own guarantee fails and God forfeits the earnest payment, which is Himself. That's as iron clad a guarantee as anyone can conceive of.
There is much more than can be said to biblically establish that those saved under the grace gospel (i.e. Paul's gospel) cannot lose their salvation. Some of which goes all the way back to Abraham but that is already sufficient to prove the point and will do for now. It really is too bad that you can't be trusted to consistently respond to substantive posts sufficient to make it worth spending the time to be thorough.
It should be made clear, by the way, that what is guaranteed is the believer's deliverance to the day of redemption. What happens after that is a different issue.