Signal is the world’s most widely used truly private messaging app, and our cryptographic technologies provide extra layers of privacy beyond the Signal app itself. Since launching in 2013, the Signal Protocol—our end-to-end encryption technology—has become the de facto standard for private commu...
We estimate that by 2025, Signal will require approximately $50 million dollars a year to operate—and this is very lean compared to other popular messaging apps that don’t respect your privacy.
The costs are distributed as there is not one single instance. Just like with Lemmy.
Although there is one huge instance on matrix (matrix.org), a bit like lemmy.ml here. But it doesn't have to be like that, they can close signups or discourage them similar to the way lemmy.ml is doing that now.
The load distributes across more shoulders automatically.
If you only host a server for yourself and 10 friends it costs next to nothing, if you have a big operation it can get just as expensive, it depends on what you are willing to do.
With centralized systems there is no choice but for the one centralized host to host everything.
Element has the same costs as Signal. So far, Element has been lucky in being able to raise money by selling support contracts to governments or companies using Matrix, but even that isn't enough, which is why Element has been raising money for the Matrix Foundation for almost a year now (with little success).
No but they do have commercial clients, even some government departments.
They're also trying to sell Element One directly to end users which involved a few bridges like connection to whatsapp, signal and telegram. Not a bad deal for 5 bucks a month IMO, though I run mine myself because I want to.
There's also beeper which sells a service with (a lot) more bridges than Element One but costs twice the price. Their company sponsors most of the bridge development as they employ the main bridge developer.