The gallery macro will be removed as announced in: We're cleaning up the macro browser

The page suggests that people insert images directly as an alternative, but as per customers feedback, this is in no way an alternative as this macro is used to display dynamic pages of images from a library based on labels.

This is a macro that is not obsolete, it's one that needs fixing so it works as it used to (i.e. you could click on the image to download it) known issue reported in the CONFCLOUD-57288-Gallery macro with style macro makes the preview on gallery macro is not working.