I'm normally on the Signal side of this argument, Telegram is trash and should not be used, but basic features like message editing are legitimate requests. I use Signal heavily and a number of times a day at least I or someone I'm chatting with corrects a previous poorly phrased or incorrectly typed messages. Because Signal has no mechanism for that, it usually involves retyping most of the message or the relevant word and adding an asterisk. I believe if Signal had built-in message editing support it would be used far more than I currently see corrections.
To be clear, I would expect Signal to allow me to see previous versions of a message and clearly indicate that it's been changed, but message editing is a valid feature that Signal should absolutely implement.
Further, the goal of Signal is not to work well for people who are accustomed to the various quirks of text-based communications that have existed since forever, but to provide a secure, modern communication client that normies don't find difficult to use. Message editing has become a standard feature of any usable modern messaging client.