A wall does not equate to border security. People opposed to a wall are not in favor of open borders. Those are scam talking points aka, lies from the liar in chief. A wall is the least effective way to achieve border security. Notice how proponents always add "sniper and machine gun equipped guard towers", "minefields" along with all the things sensible people are asking for such as drones, electronic surveillance, additional manpower, more judges and effective courts, etc. Leave out the scam points being made to satisfy the ego of our narcissistic asshole President Trump and end this costly charade.
A wall is a huge part of border security and it won't be the solution for every case. However in many cases, it will stop or at the very least, extremely slow down the border crossers. It also acts as a deterrent.
So why are your puppet masters telling you it won't do any good even though there is zero evidence of their claim? Because a wall cannot easily be removed. Democrats know a wall will provide positive results, but they don't want to stop this flow of illegals. They want it to continue and expand, it's just they can't tell you that.
Democrats only want solutions they can get rid of once in power again so they can get more illegals into the country and not take any blame.