I can simply "print" or "say" whatever html I want straight out to the browser

You can indeed. You can even do it with Here Documents and there are times when that is appropriate...

But - and it's a big but - it would be time well spent to get to grips with one of Perl's many templating systems. Thanks to The Monastery, I took the plunge a couple of years back and have no regrets for the time invested. Personally, I use Template but there are plenty of others to choose from.

If you grow beyond your current requirements, say more complicated use of HTML/CSS/JS you may want to consider a templating engine or framework. I use Mojolicious, it has a powerful and easy to use rendering methods which make life so much easier.