Schumer doesn't want to spend billions on something that won't provide any more security than the current system, which is what experts (literally the people who design and build border walls for a living) are saying. You can disagree all you like with them, cool, but don't categorize blocking the wall as not wanting border security.
If you put a quarter of the money he's asking for into the existing system, hiring and equipping more ICE agents, more judges, and more social workers to process undocumented immigrants faster, you'd get a better result than this ridiculous wall.