I think in this day and age, it's "fine I guess" that it's set up that way: most services do that. But going forward, I think it's much better if services work in the way that e.g. email and IRC work: decentralized and federated. Nobody can know what will happen with Signal, or the USA in general. We'll be having this whole conversation about switching chat clients again in a couple of years. Whereas with a decentralized service, it doesn't matter. Anyone can build the software, anyone can run a server. Regardless of what happens to the people or organizations behind it.