It's definitely a more difficult model. Open source projects tend to attract very opinionated people, and a project's infancy is when it's most fragile. Usually the objections come from the outside, but at Mozilla the critics are the core volunteers who (publicly) question weather project decisions are aligned with the manifesto [0] all the time. It's also seen as inappropriate when someone tries to develop something in private and then release it expecting it to be shielded from criticism because it's more polished than a prototype.

All of this means you can't get away with shady stuff, or cool stuff that doesn't align with the project. But products need to evolve to stay competitive, and the downside is that the added friction from having to respond to people who are not in the payroll about what to develop and what to release means Firefox doesn't have the capacity to move as fast as Chrome does, for example.

[0] https://www.mozilla.org/about/manifesto/

Furthermore, Chromium's now spent the vast majority of its life developed in the open. You would probably find today's code unrecognizable if you traveled through time from 2008.