1.Fdroid 2.Nextcloud 3.Matrix/Element

Thank you :-)

I feel like we don't have an integrated Foss ecosystem yet, despite the many good app alternatives

Code

is a Motorola G8,I think to use only with Fdroid, but G Play is a persistent and invasive application

Thanks for the suggested path :-)

The smartphone is from the company, I can't install another OS. But I can "ungoogle" as much as possible.