A snipe will not save you $ against another algorithm based bid. As you say if someone has a max bid above yours it will win. But if your competition is a person entering another bid manually to outbid you, you will win (if it doesn’t exceed your max bid.) No way for them to enter another bid manually fast enough to win. If you enter your max bid early someone has time to bid it up and figure out your max.
If an item sits at $5 for the last 3 days of the auction a person may enter $10 in the last few seconds. If your max bid is $15 you will win at $10.50 because of the algorithm. I’ve lost auctions using a sniper. But I’ve won many more.