Why is it called case "folding"?

[Andreas Prilop]

On 17 March 2022, Asmus Freytag wrote:

>>> Content-Type: text/html
>>> <pre class="moz-quote-pre" wrap=""> 
>>
>>  Wonderful! 
> 
> And your point being?

You (or your user-agent) send messages as “text/html” with “<pre>”,
which prevents wrapping of lines. The reader has to scroll horizontally
or sees the message in a tiny font size.
See your own message at:

https://corp.unicode.org/pipermail/unicode/2022-March/010065.html

https://corp.unicode.org/pipermail/unicode/attachments/20220317/a8b80bc4/attachment.htm

Why are you sending text/html in the first place?
You do not have any formatting at all.