How to remove wp panel for users

First of all, you should never use current_user_can function with roles. You should use only capabilities as params, as Codex clearly states:

While checking against particular roles in place of a capability is
supported in part, this practice is discouraged as it may produce
unreliable results.

So, if we’ve dealt with that major issue…

There are 2 things you have to do, if you want to disable wp-admin for subscribers:

1. Hide Admin Bar

Admin bar is the dark bar displayed at the top of a page, when user is logged in.

You can hide it using this code:

function remove_admin_bar() {
    if ( is_user_logged_in() ) {
        $user = wp_get_current_user();
        if ( in_array('subscriber', $user->roles) ) {
              show_admin_bar(false);
        }
    }
}
add_action('after_setup_theme', 'remove_admin_bar');

2. Prevent wp-admin access

function restrict_wpadmin_access() {
    if ( ! defined('DOING_AJAX') || ! DOING_AJAX ) {
        $user = wp_get_current_user();

        if ( in_array('subscriber', $user->roles) ) {
            wp_redirect( site_url( '/user/' ) );  // <- or wherever you want users to go instead
            die;
        }
    }
}
add_action( 'admin_init', 'restrict_wpadmin_access' );

If you want to target different user group, all you need to do is to change this line in both functions above to match your needs:

if ( in_array('subscriber', $user->roles) ) {