I'm all for Signal and E2EE and distributed systems and all that, but... Telegram is, by far, the least-bullshit most-fun messenger I've ever used. Everything just seems to work, it's lean, has native open source client apps, a big pile of features *that are cohesively integrated* and *work*, API/bot support, useful stuff like automatic translation (premium feature, but that's understandable since translation APIs aren't free), etc.
Other platforms would do well to learn from it.