The questions come in:  "Why do my fruit look like this?"

Well there are often simple explanations.  And often there are complex ones.  But one way to start looking at a piece of fruit damage is to consult this wonder color brochure put out by UC - https://anrcatalog.ucanr.edu/pdf/8090.pdf

This catalogs the most common fruit disorders - not all - but most that we see.  Sometimes it requires more sleuthing, but start here first to get some answers and possible solutions.