The spring is just to make it foolproof.
Canned foods generally go in hot and create a vacuum when they cool. Fermented foods generally go in at room temperature and do the opposite due to gases releasing during the fermentation process. They create pressure instead so the spring allows gases to escape but don't allow any air to get sucked in(like at night when the room cools off). It's like a check valve.
You can tighten a regular lid about the same as when canning and it will work fine because it will allow pressure release but vacuum will pull the lid down and the gasket will seal it but not so tight pressure can't release again.
There are people who make homemade wine in the plastic bottles that 100% fruit drink comes in and they just lightly snug the cap. Wine is fermentation and acts the same as any other type. Bubbles/gases must escape but you don't want air with possible airborne fungi to get sucked in.
Actually I got it, I was kidding kind of .....