The graphics primitives the web provides are actually not that great at emulating Flash's specific graphics model. SVG and canvas differ from Flash in a few key areas, especially to do with masking; and WebGL/WebGPU are very low-level and rendering vectors on GPU is hell.
This could have been fixed by having Animate switch to an SVG+SMIL renderer for HTML5 projects, but Adobe wanted a quick fix to keep Animate relevant beyond Flash Player.
The graphics primitives the web provides are actually not that great at emulating Flash's specific graphics model. SVG and canvas differ from Flash in a few key areas, especially to do with masking; and WebGL/WebGPU are very low-level and rendering vectors on GPU is hell.
This could have been fixed by having Animate switch to an SVG+SMIL renderer for HTML5 projects, but Adobe wanted a quick fix to keep Animate relevant beyond Flash Player.