Do you use a device with open source Android firmware? What device, which distro and what do you do with it? I have a Samsung tablet with LineageOS and apps from F-Droid. Other than displaying dire warnings about the unlocked bootloader every time it cold boots, It’s great for a “recliner system”: email, Web browsing, E-book reader and MP3 player. What do you have, what do you use it for, and how well does it work for you?
I use a SHIFT6mq with GApps-less LineageOS and only apps from F-Droid.
And I do lots of things with it. Media consumption, email, web browsing, music, social media, RSS, messaging, note keeping, shopping list, navigation tool (map & public transport), ticket wallet, 2FA etc…
I don’t care to use proprietary services, so not having access to the respective apps is not a problem for me.
Really, I’d want it to be even more open. Android has some real limitations to it, like no way to just quickly script something, and just generally, it disallows apps from doing lots of useful things, because it assumes apps to be malware.