What are the potential drawbacks of using PHP's sleep function for implementing delays in web applications, especially in the context of user experience?

Using PHP's sleep function to introduce delays in web applications can lead to poor user experience as it halts the execution of the script, making the page unresponsive during the delay. This can result in a negative impact on user interaction and may lead to frustration. To implement delays without affecting user experience, consider using asynchronous techniques like AJAX calls or JavaScript setTimeout function.

// Example of implementing a delay without using sleep function in PHP
// This code snippet demonstrates how to set a delay of 3 seconds before executing a task

// Output a message to the user
echo "Task will start after 3 seconds...";

// Set a JavaScript timeout to delay the task execution
echo "<script>setTimeout(function() { 
    // Task to be executed after the delay
    // For example, redirecting to a different page
    window.location.href = 'new_page.php';
}, 3000);</script>";