My experience with nostr (where you generally have ~200 people you follow and many reposts from other people too...) is that it eats a lot of data on images and gifs, e.g. 20GB per month.

There are probably 1000 users per relay (just guess) and so a relay may need to transfer 20TB per month, which seems prohibitively too much in 2023 for majority of people.

So if the network is only couple people in mostly closed circles, then it's possible, but for more open networks (like nostr), I think the data would become issue quickly and force centralization on only couple relays. And that's why the nostr model, where binary data hosting is done using centralized services, seems reasonable.