I think we are missing some contexts here. I have been trying to find more information about them. From what I found [1] (hopefully accurate) it looks like they are a new team - Beta in August 2021 and just incorporated in this February. The founder/CTO is a full stack developer. I speculate they are a very small team (1-2 developers at the most) and a relatively straightforward architecture. In that context I suspect it is quite feasible to go from local to production without going through staging: They are likely to have a self sustained stack that can be packaged; they don't have a huge database or collection of edge cases; they have few customers, low expectation in terms of service level; they don't have stakeholders to review and approve features done (they are their own bosses). I emphasize with where they are, I have been in the same place at some point. It will be interesting to see whether this is sustainable without staging, or for how long, as they grow in team and offering.

[1] https://www.indiehackers.com/product/squeaky