Bear in mind OCR is often working on screen grabs, not on scans or photos. It still won’t be 100%, but it’s a good kind of text to try to recognise.
I note that Mastodon’s Web UI offers an OCR function in the dialogue where you can enter an image description for accessibility reasons. It might be that it runs server-side. Here’s what it looks like, after I clicked on “Detect text from picture”:
