IMHO in this video the end result doesn't qualify as ASCII art - square letters in particular are a deal breaker to me.

It is still a cool shader that turns input into text, even if it doesn't have the ascii art vibe.

ASCII just refers to the 7bit standard, so if we are pedantic ASCII art is just art using the printable characters of the 128 code points defined in it. Font size doesn't have anything to do with it. But ASCII art is used as an umbrella term, encompassing a variety of different standards, character sets and fonts. There are a bunch of square ASCII, like PETSCII, ATASCII and even PC ASCII can be rendered with a 8x8 cp437 font. We don't need to gatekeep what "qualifies" as ASCII art.

> There are a bunch of square ASCII, like PETSCII

Note that e.g. PETSCII, while internally 8x8, would be displayed using non-square pixels[1] - also not resulting in square letters.

[1]: https://retrocomputing.stackexchange.com/a/13871

“goes into depth”

I see what you did there

(without intending to do it)