What's with all the weird restrictions on using Signal? Why do I have to register via an Android account? Why not a simple messaging app that just lets me messa

What's with all the weird restrictions on using Signal? Why do I have to register via an Android account? Why not a simple messaging app that just lets me message anyone else with the app with no bullshit? Signal has done an excellent job of branding itself as the one true E2E encrypted messaging app made by real experts, as against e.g. Telegram. But the actual product is hugely disappointing because of these apparently arbitrary and, in the case of requiring a phone number, privacy-damaging restrictions. I'm ready to look for something else.