Blender is the free and open-source 3D creation suite. It supports the entirety of the 3D pipeline—modeling, rigging, animation, simulation, rendering, compositing, video editing, and motion tracking.
Blender vs Apple Motion opinions
Blender is great, but it is no where near a tool oriented for creating motion graphics for video production. Yes, it can generate animation, but it isnt designed to fit into a NLE workflow.
Blender is an alternative, not a good one, though. At least it depends on the perspective. Blender is extremely versatile and feature rich. Motion graphics and compositing are just two features while those are the main purposes of Apple Motion. So differs the learning curve. Apple Motion is a lot easier to get started with. Blender improved over the years but its unconventional already in the user interface. I would say Apple Motion is the easier choice on macOS.
Blender is more of a (failed) animation program.
Natron is an open source, cross platform nodal compositing application. It is built around industry standard open source tech such as OpenFX, OpenEXR, OpenColorIO and OpenImageIO. The feature set includes realtime playback/RAM cache, multi-threaded rendering, 2d tracking...
Natron vs Apple Motion opinions
Is also node based and it's open source
Adobe After Effects is the premiere digital video effects software used industry wide for film making and TV production as well as creative work including high-end video intros and audio-reactive music visualizers.
Adobe After Effects vs Apple Motion opinions
Produce videos for the web using the industry-leading H.264 format. No tweaks or technospeak, just sparkling HD-quality video with compact file sizes...every single time. Two existing production presets (blog and web) and three new presets (YouTube, HD display, and Screencast.
Bforartists is a complete 3D suite to create 3D content. It offers you the full 3D art pipeline to create game graphics, prerendered movies and stills.
Blackmagic Fusion (formerly known as Fusion and eyeon Fusion) is an image compositing software program created by eyeon Software Inc, now developed by Blackmagic Design. It is typically used to create visual effects and digital compositing for movies, TV-series and commercials.
NUKE is a powerful compositing application that delivers unparalleled speed, an efficient multi-channel scanline rendering engine, and a first-class feature set that is unrivalled in the desktop market.
picoCAD is a program to build and texture lowpoly 3D models. Programs for modelling are overly complicated, picoCAD aims to make it fun, easy, and accessible by focusing on the bare essentials. This program was made using pico 8.This app doesn't have any features at the moment.