Hmmm... Got me thinking, why must all software implement (and maintain) transport security?
The security standard changes/improves over time. With software like stunnel takes care of it, your software could be practically security wise up-to-day forever as long as you or your user keeps their stunnel updated.
I use Caddy the same way. My web apps aren't allowed to think about TLS, they sit behind Caddy and I'm secure as long as I keep it updated
That's basically the idea behind zero trust, isn't it? The idea being that you can't even knock on the TCP port if you're not authenticated