Hi,
having an Android phone as secondary, I would say:
best would be a custom rom like grapheneos (Pixel only), lineageos or e/os. They come with plenty alternative apps from the getgo.
Most Fossify apps are on F-Droid. They used to be known under the name “Simple Mobile Tools” and presented with orange app icons. The original author sold their brand/their userbase to an adware company, but the project lives on in form of this community-driven fork.