Because they don’t really want to do the things they tell you they’ll do when they want your vote.
Congress is broken because of the openly pro-Islamist, anti-American nature of the Democrat Party and the cowardice of the RINOs. We need people to acknowledge that and to insist that Congress give Trump extensive emergency powers for a year or two to, allowing him to enact the MAGA agenda that a clear majority of Americans are aching for.
Congress could then stick around to oversee the project, or better yet, GO HOME and suspend its operations until the emergency decree expires.