loading css file via functions.php

I have been trying to work out why I can't get my css page to load using the wp_enqueue_scripts method within functions.php in my theme folder.

Here is the most simplified code currently that I am still having issues with, hopefully someone will notice something, if not at least assist me on where to diagnose next as I don't see anything with php and wordpress errors turned on.

function my_assets() {
	wp_enqueue_style( 'main-style', get_bloginfo('template_directory') . '/css/style.css',  '1.0', 'screen' );

add_action( 'wp_enqueue_scripts', 'my_assets' );
echo get_bloginfo('template_directory') . "/css/style.css";

I can see that the path to the css file is correct and it's also accessible. I know that my css file works as I can load it via expressing the path in the header, it's just I am trying to follow the best method and I have many additional css and js files to eventually load too and believe this is the method needed.

Currently I've just spun up a fresh vps with basic out the box WordPress installed and my theme moved to here, again with debug enabled I don't see any errors at all, yet the page is lacking the styling which does work if loaded a different way.

What can I possibly do now as I am at a loss after spending a full day reworking this over and over with no success and no obvious errors.