This question comes up often on r/MotionDesign and r/UXDesign, usually from designers who want to add motion to their skill set.
Lottie
If you know After Effects, you can make Lottie files this week: build with shape layers and export with a plugin. If you only know Figma, the LottieFiles plugin and Lottie Creator get you there. The ceiling is interactivity: Lottie is mainly a timeline, with dotLottie state machines as a newer layer on top.
Spline
Spline feels like a friendly, browser-based 3D tool. You can make an interactive 3D hero in an afternoon. It is the wrong tool for 2D interface components.
Rive
Rive asks you to learn its design tools, its animation mode, state machines, and increasingly data binding and scripting. Designers on Reddit commonly describe a few weeks to feel comfortable and longer to master it. In return you get files that react to app state across platforms.
Where ExodeUI fits
ExodeUI works like Rive in that it pairs an editor with state machines and runtimes, with a focus on UI layout, spring physics and AI tools via MCP. We make ExodeUI, so try it alongside the others.
Our advice
Making marketing or illustration motion? Start with Lottie. Making 3D web scenes? Spline. Making interactive product UI? Learn Rive or ExodeUI.