Yes Vaseline and Petroleum Jelly is good for and does help electrical connections.
The Vaseline or Petroleum Jelly helps the electrical connections by keeping moisture off the electrical connections which helps prevents corrosion on the electrical connections.
That corrosion on the electrical connections can cause the connections to not conduct the electricity properly and then cause electrical issues.
The corrosion can also cause the electrical connections to fail.
You can also put Vaseline on battery terminals which helps prevent corrosion and helps the connections stay in good condition.
Poor battery connections can prevent your vehicle from starting and prevent your battery from charging properly.
You can also use dielectric grease on the battery terminals or electrical connections to keep the connections in good shape but Vaseline also works well.