Isn't something like <https://3v4l.org/09AB3> even more nice,
since it actually prints a dummy text?

You do not understand!. 
Required work without error NOT <?= 'Example' //Example ?>. 
Requires error - free operation for <?= // ?> and <?= //Example ?> and <?= ?>.
Script itself <?= ?> should not cause errors.

<?= "" //$val ?>

If you want to push for this change to the language then use the RFC process. https://wiki.php.net/rfc/howto

> You do not understand!

you don#t

> Script itself <?= ?> should not cause errors

it should simply because it's the short form for <?php echo; ?>

php > echo ;
Parse error: syntax error, unexpected ';' in php shell code on line 1