"some way to protect metadata (e.g. self-hosting)"
is incompatible with Wire. Let's not just scream product names without understanding if it's for their threat model. If you're here to promote Wire then I perfectly understand why you'd recommend it anyway.
Yeah, Wire failed my requirements, but I probably should have mentioned it. (I simply forgot about it when I was posting.)
There's the issue you mentioned, and there's also the issue of them violating their published policy (either by the letter or in spirit) when they accepted new owners/investors.[1] Even if it met my requirements, I would be leery, and reluctant to suggest that others invest their time and build their communications network on such a foundation.
Of course, things can change over time. Maybe Wire will do things differently in the future, and become more appealing. That doesn't solve a problem for me today, though.
For the record, there's some discussion of Wire and other apps scattered about the privacytools.io issue tracker[2]. The signal:noise ratio there isn't great, but some folks here might find it interesting. As long as I'm posting links, their main site is worth a look, and the section about instant messengers[3] relates directly to this thread.
IMHO we should be able to determine the amount of trust we can put on the app from the client alone. If FOSS client uses E2EE, no matter what the server starts doing when the service changes ownership will have an effect on it. Of course the new owner could e.g. start selling user metadata, but that's something you should kind of assume the service is doing anyway (just because they can), and if you can't take the risk, you should use something that prevents it by design (like Briar/Cwtch/Ricochet/TFC).
I agree in principle, and I look forward to the day when all my requirements can be met without self-hosting or trusting another party with metadata. After all, most people don't have the means to self-host. Multiple projects (including Matrix) are working in that direction, but I'm not holding my breath; metadata exists at multiple layers, and is a hard problem to solve.
Until that day, a public host with the right incentives and track record remains valuable, even if only to include people who don't have tech-savvy friends to host for them.
Regardless of all that, given the choice between rewarding an organization with good behavior vs. one with bad behavior, I choose the former.
What's the issue with self-hosting? It's not that expensive to run a netbook 24/7 with an Onion Service. I'm doing that for my FreedomBox with radicale etc. ATM.
There's no overhead costs like static IP or hostname.
I can agree with the point of "average user lacks the skills" so that's something that needs good tutorials.
But then there's apps like Briar that just run on your phone, that bring the complexity down to these users.
is incompatible with Wire. Let's not just scream product names without understanding if it's for their threat model. If you're here to promote Wire then I perfectly understand why you'd recommend it anyway.