Alt-text doesn't just mean accessibility in terms of low -vision or no-vision end users.
Done right also means accessibility for people who might not know much about your image's subject matter either.
This is especially true for technical topic photos. By accurately describing what's in the picture, you give context to non-technical viewers, or newbies, as to exactly what they're looking at, and even describe how it works or why it matters.
#AltText is not just an alternate description to a visual medium, it's an
enhancement for everyone if you do it right.
(So I can't find any prior post of mine on this, so if I've actually made this point before, well, you got to hear a version of it again.)