It is not Android that is the problem, but Google - the old data octopus - that is behind it everywhere.
And Google sees the user IPs and knows who is behind it. Big Data in the global sense!
But there are enough solutions:
Set up your smartphone with an ungoogled Android. Use secure keyboards (e.g. OpenBoard).
Signal is a data slinger - in the sense of the US intelligence services. But it is not a secure messenger.