Them fart concerts in the bathroom after lunchtime

What's the general Software Engineering rule of thumb again for frontend templating code?

If I look at certain websites, I notice some code smells in PHP such as:
$.modal = <?php echo $(base)["username"] != 'me' ?' ': echo 'style="display=none"' ?>

or just in general places in the code where PHP gets used as a templating engine for gluing together pieces of HTML code based on conditionals spread out over the codebase and the database itself too. To make things worse, this carries over to JavaScript ajax functions. As a developer, this to me just seems like spaghetticode.

On the other hand, many popular frameworks properly do templating, such as EJS, containing templating in one place and not mixing it with logic too much but just having simple output like <%= %>.

I know I've seen frameworks like Angular 1 contain pieces of HTML into directives, but maybe that's something different, more 'OO'-simulating or cleaner.