On the other hand, you will have an absolute pain trying to transfer messages to another device. To move from one android device to another you have to manually make a database backup (hope you didn’t lose your old phone!) and copy it over to a new phone. Moving from an iPhone to another iPhone is slightly better since you just have to have both iPhones and then the app can sync the data across. However if you try to move from Android to iOS or vice versa, you are absolutely screwed. There is no way to get your data transferred to your new device and there is no way to get your data out of signal, even the database backup the Android app has doesn’t include everything. Say what you want about WhatsApp but at least thanks to GDPR my data isn’t permanently trapped in one app forever with no way to get it out.
Just use Signal. It's free, open source, and end-to-end encrypted.
https://signal.org/