$users = [
    ['id' => 1, 'name' => 'Alice'],
    ['id' => 2, 'name' => 'Bob'],
    ['id' => 3, 'name' => 'Charlie'],
];

To get all the names:
$names = array_column($users, 'name');
// Result: ['Alice', 'Bob', 'Charlie']

Want to index them by ID?
$names = array_column($users, 'name', 'id');
// Result: [1 => 'Alice', 2 => 'Bob', 3 => 'Charlie']