It makes sense to talk about Signal in these types of threads, despite not being about Signal, because Signal is still the de facto private messenger. The userbase is much larger than that of Threema so it is worthwhile to compare how these platforms are doing things differently. Especially in the context of if users should switch. Just like how in threads about Signal it is similarly appropriate to discuss WhatsApp and Telegram (and vise versa). Though I'll admit that these conversations can degrade into flame wars and get off topic quickly.