I think part of the issue with Ello was that they sell themselves as non-corporative social media while maintaining two of the most important characteristics of corporative social media:
Centralisation and lack of federation
Being closed-source
The story would have gone completely different if they
Had made it open-source allowing users to contribute to the project, both as devs and through donations.
Added decentralisation and federation, allowing others to make their own Ello servers. This could have taken a lot of weight (financial and otherwise) from the developers/founders. Users cost money. Dividing the user base within different servers, pay by and moderated by different people means dividing the costs.