I LOVE TEXT AND I HATE STRING PARSING
Yes this is hypocratical. On one side I love that I can netcat to an SMTP server, complete the authentication and write my message. This requires the protocol to be constructed such that a human may understand it solely by looking at the protocol messages. This is why I think the older protocols will never die. They are simple and can be used with simple programs. I love SMTP, I love IRC, I love FTP, I love IMAP, I love POP, I love the old HTTP protocols.
On the other side these human readable protocols are a nightmare to code. They need to handle strings and string parsing is really hard. It is better to have a defined message structure for developers. Otherwise it becomes a security nightmare. This message structure ideally should not be variable length. IPv4 made the mistake of including useless options field which makes it a variable length.
Looking back protocols have evolved from defined message structure, binary protocols like Ethernet, IP, TCP, UDP, OSPF, BGP, DNS etc. to human readable protocols (like the ones I have mentioned) and then back into binary protocols like HTTP/2. I don’t see these human readable protocols coming back though. But I also don’t see them dying either.