Guavas are quite commonly eaten raw here in Brazil. Maybe you haven't let them ripen?

Anyway as an amusing side note, as I understand itbin the Northeast of Brazil "marmelada" is idiomatically used to express that the speaker isn't going to be fooled[1], though its usage may have passed out of style right now. I had assumed it had something to do with a distaste for bitter orange marmalade (even though I have seen it for sale in supermarkets here). I guess there could be a story related to the Portuguese quince condiment instead. Hopefully I can find out one day.

[1] learned when asking about the Margareth Menezes song called Marmelada https://youtu.be/LoNMVUaNmeE

How are guavas hard to eat raw??? I've literally lost count of how many guavas I've eaten.

The skin is kinda gross, and there are many small seeds.

Some people who don't like the skin peel them. I don't bother. The seeds likewise aren't a problem for me at all.

Ripe guavas are one of my favourite fruites. Unripe guavas are tart and hard to bite.

Unripe guavas are very popular in South-East Asia, typically served with either dried prune powder (asam boi) or, in Thailand, chilli flakes.

This is also available in Portugal, and it's even better.