Function to consider a plugin activated for selected users only

yes, this is possible by creating a new function because thank to wordpress function activate_plugin() that can be used to activate the classic editor plugin for specific users

// Define the usernames of the users who should have the Classic Editor 
enabled
$CE_users = array('user1', 'user2');

// Check if the current user is logged in and their username is in the array 
of CE users
if (is_user_logged_in() && in_array($current_user->user_login, $CE_users)) {
// Activate the Classic Editor plugin
activate_plugin('classic-editor/classic-editor.php');
}

Add this code into Your theme functions.php file of your child theme and see it’s working or not