Comment by joshjob42

This isn't fully accurate. You can backup your Signal messages on Android with an encrypted file and a key you control. So yes, just installing on a new device isn't going to give you history. I'd prefer they offer a universal structure for that backup file so we could easily switch between Android and iOS and have some way to backup your data at all on iOS (presently if anything goes wrong when setting up a new phone you lose your entire message history).