I'm using a Librem 5 as my daily phone. PureOS is actively developed and based on Debian. Monthly development updates are published here: https://puri.sm/posts/tag/advanced-readers/
Personally, I do not use Android apps on the Librem 5, but Waydroid is available in the PureOS repository. Waydroid is a container-based approach to boot a full Android system on regular GNU/Linux systems running Wayland based desktop environments (like PureOS).
PureOS also provides convergence via Phosh. Convergence means here that the same app can be used on a phone and on a big screen, the GUI adjusts to the available screen size.
Phosh aims to provide a daily-usable, robust and easy to use graphical user environment for mobile devices running mainline Linux. Phosh was originally initiated by developers from Purism for the Librem 5 phone but is nowadays used on many different devices covering smartphones, tablets and convertibles. It has even been seen on laptops.
It will be a long tough uphill battle, but digital freedom is possible.
Purism is for example providing the Librem 5 phone with PureOS. Closing the app gap is big challenge, but I use the Librem 5 as my daily phone. Yes, I may have some inconvenience, but I have freedom, and the software is getting better and better.