Buy European

You may want to clarify which parts you want to replace. As a whole suite, there isnt anything I am aware of, but each individual part usually has one or more open source alternatives

Yep, most things on that list are not drop-in replacements for these products at all, as you're supposed to change your behavior entirely. i.e.:

• For Nextcloud, you have to self-host or to search for a provider. Nextcloud themselves aren't offering any cloud services;
• Same for Element (which is Matrix);
• Flashes is just Bluesky, but with only photos - these same photos can be posted on Bluesky directly.
• ReVanced as an alternative to YouTube? You gotta be joking.
• Stremio - if you're not looking for piracy, then this is not for you. But it's a nice touch though
• Immich - you can only self-host it
• Brave; Firefox - they're the lesser evil, yet they're still American
• For Droid-ify - you gotta jump to Android first. If you want to stay on Apple, use Alt Store

Probably the most feasible things for the regular folk to jump to are Mastodon, PeerTube, Pixelfed, Lemmy (self-hosting is not mandatory), Jitsi, Ecosia, LineageOS (if they switch phones) and Linux Mint (or any flavor of Linux for that matter).