I like and have paid for image hosting services for nostr, but I expect >98% of your expenses are tied to free tier business with people who will never pay. In a way, you will always be your own biggest competitor.
I appreciate that jack and many have gone into their pockets to bootstrap nostr. I have poured in about 550€ on my small relay. But, if we don't build decentralized profitable micro services into the system we will just get the same centralized outcomes when the generosity runs dry. If nostr survives and thrives as a protocol, then a microservice economy of image hosting dvms will likely replace centralized hosting services.
Here is my guess at *a way* to solve relay sustainability with P2PK https://habla.news/a/naddr1qvzqqqr4gupzq8v8t8lufpnm6d0pryn7n629a4j5nsppaspszad65wv5htazp38eqqxnzde3xyuryv3kxu6rgve4pxhc20
Maybe there is something there that may inspire a future image hosting micro service.