I think it is well worth giving AMP a try. The web pages include the latest JavaScript and the progressive web pages load really fast. Many large organisations are using the framework and you may have noticed that Google shows a little icon in their search results for valid Amp web pages.
Basic page from the above link:
<!doctype html>
<html ⚡>
<head>
<meta charset="utf-8">
<link rel="canonical" href="hello-w<br>orld.html">
<meta name="viewport" content="width=device-width,minimum-scale=1,initial-scale=1">
<style amp-boilerplate>body{-webkit-animation:-amp-start 8s steps(1,end) 0s 1 normal both;-moz-animation:-amp-start 8s steps(1,end) 0s 1 normal both;-ms-animation:-amp-start 8s steps(1,end) 0s 1 normal both;animation:-amp-start 8s steps(1,end) 0s 1 normal both}@-webkit-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@-moz-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@-ms-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@-o-keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}@keyframes -amp-start{from{visibility:hidden}to{visibility:visible}}</style><noscript><style amp-boilerplate>body{-webkit-animation:none;-moz-animation:none;-ms-animation:none;animation:none}</style></noscript>
<script async src="https://cdn.ampproject.org/v0.js"></script>
</head>
<body>Hello World!</body>
</html>
PHP Version:
<?php
declare(strict_types=1);
error_reporting(-1);
ini_set('display_errors', 'true');
$title = 'hello-world.html';
$style = file_get_contents( 'ampboilerplate.css' );
// using PHP HereDoc String Type
$ampPage = <<< ____TMP
<!doctype html>
<html ⚡>
<head>
<meta charset="utf-8">
<link rel="canonical" href="$title">
<meta name="viewport" content="width=device-width,minimum-scale=1,initial-scale=1">
<style amp-boilerplate> $style </style></noscript>
<script async src="https://cdn.ampproject.org/v0.js"></script>
</head>
<body>
<h1> $title </h1>
</body>
</html>
____TMP;
echo $ampPage;