The drag brace strut is an "overcenter" locking strut. It has a "knee action" to provide a kind of passive locking function because when moved into its overcenter position, compression forces a can only try to overcenter it more, which is prevented by the contact lugs above the center pivot and it can only fold going the other way.
It works the same way as your knees when standing. You can keep your knees bent slightly so that your weight is trying to fold your legs up. If you bring your knees back while standing as far as they will go, they "overcenter" and your weight can only try to make them overcenter more, which is prevented by the bone structure of your knees. So when you stand up from a knee bend and your legs go into that overcenter lock mode that allows you to relax your thigh muscles, your legs are "down and locked".
While standing like that, some trickster might come along and bump your knee from behind and break the overcenter, making you start to fall before your thigh muscles can take over.
Or someone could lift you up just enough to let the compression load on your legs be released and then let you go, and might find that your knees moved forward of the overcenter axis as your weight comes back down on them, and down you go before you thigh/butt muscles take over.
The springs are there to prevent that in the case where temporary tension is applied when the gear comes under load, bringing the strut out of overcenter to on-center; when compression is re-applied, without the springs it could go either way, back into overcenter or out of overcenter, and collapsing, like your legs. The springs guarantee that the brace will always move back to the overcenter position unless forced out of it by the drag brace actuator.