I wish people would ask this question of IPFS more often. Storage, especially long-term storage, requires incentives! Just look at BitTorrent -- at best, you continue seeding a file after downloading it out of the goodness of your heart, or (more commonly) because you can't be bothered to remove each torrent file after it finishes. In practice, the only way to keep torrent files alive for a long time is out-of-band incentives, primarily in the form of "points" on a private tracker. Even then, seeders have little incentive to seed content that isn't personally valuable to them, since they can get just as many "points" for seeding an equal amount of valuable content. In other words, good luck finding high-quality seeders for your personal photos. Ultimately, if you want someone to store your data, you need to pay them (in traditional currency or otherwise)!