Now that Apple Creator Studio is out what do I have that (sort of) replicates it:

Pages: Create Documents
Numbers: Make Spreadsheets
Keynote: Design Presentations

• These three don't need a replacement since they're still free to use with only a few features paywalled.

Final Cut Pro: Create Video

• Apple's iMovie seems like the logical choice for amateur video creation

Logic Pro: Make Music

• Apple's GarageBand is pretty nice though I only use it to record podcasts
• Audacity - similar to GarageBand in terms of recording, I use it to compress my podcasts to 22kHz mono as Garageband doesn't have a way to compress it that low
• Levelator v3 - great for leveling out podcast sound, though now only available on Archive.org

Pixelmator Pro: Edit Images

• I have the old Pixelmator Pro from the Mac App Store. Might no longer get updates but for now it works fine.
• Affinity Studio is free (subscription for AI features). It does pixel and vector graphics and page layout.

Motion: Animate Effects

• Not sure if iMovie can do any of this.

Compressor: Encode Media

• Handbrake is more of a way to encode video for different devices but along the way you can reduce file sizes.

MainStage: Perform Live

• An unusual app that I don't have any alternative.