Images should not normally have text embedded in them either. Embedded text can not be read by screen readers, and sometimes is not easily viewed for those with visual impairments.
Modern CSS styles, combined with images set as backgrounds, can have the same effect and still be usable for those with impairments.
If there are images where text must be embedded in the image, write the alt tag so that the text in the image is written out, unless that text appears next to the image as well.
On some social media platforms, using text embedded in an image may be the only option. In those situations, make sure the descriptions/alt tags include the text of the image.