I think i have 3 big criteria:

• Track record
• Structuring things to pre-emptively keep themselves (and more importantly, those who might take over later) honest and aligned with the collective good
• Good people involved and ideally in charge of the project

Other people have mentioned things like venture capital and that’s certainly something to bear in mind (arguably part of the structure), but there are projects like Matrix where that feels quite marginal to me, the aforementioned aspects more than make up for it.
Like when the main figurehead of the project goes on stage and nerds out about the code, that’s a pretty fucking good sign in my book.

it’s basically the exact same thing as i’ve seen with IRC, people keep saying it’s decentralized and then when asked to show an example they just go “yeah well uhh obviously it’s not externally decentralized duhhh! It’s ✨internally decentralized✨” which just means they protocol makes horizontal scaling easy…