yes, at the moment it's hard to earn money from renting out diskspace. (I've got a few nodes out there) Maybe investing is the better idea. Because even if you have petabytes of diskspace... you need someone who is willing to rent it.
So let's hope that the user base will grow... maybe with the nextcloud-sia-storage-backend-thing ;)
https://nextcloud.com/blog/introducing-cloud-storage-in-the-blockchain-with-sia-and-nextcloud/