Lists that rank "most used" animation software rarely cite data. Here is what is widely used by kind of work, which is the more useful question.
Motion graphics and video
Adobe After Effects is the default in agencies and studios. Cavalry and Blender are growing alternatives.
3D animation
Blender is free and open source and has a huge community. Autodesk Maya is common in film, TV and game studios. Cinema 4D is popular for motion design.
2D character animation
Toon Boom Harmony is widely used in TV production. Adobe Animate, TVPaint and open-source options such as OpenToonz and Krita are also used.
UI and product animation
Figma prototypes are where most UI motion starts. Lottie is the most common format for played animations in apps, usually exported from After Effects. Rive and ExodeUI are used for interactive motion that ships; we make ExodeUI. Developers use Motion, GSAP and CSS on the web, and Reanimated or native APIs on mobile.