No, it's no longer practical for any purpose. I mostly use openssl instead, e.g. for testing if my SMTP server is up and has a valid cert:

openssl s_client -connect myhost.com:25 -starttls smtp

Telnet stopped being useful a long time ago, is no longer shipped by default, and there are better tools to do things it was used for decades ago.

Good, so you understand perfectly the reasons for us all attempting to abolish use of port 80.

I think everybody understands the benefits of HTTPS, there is no need to discuss that. But the fact remains that forcing everybody to move, even old static websites where potential impersonation and MITM attacks matter little, turned out not so painless as the advocates had proclaimed.