> The working resolution must be 1920x1080 or higher throughout the production, including drawing, scanning, background, CG and VFX.
At least a few years ago, there was a belief that most anime were produced at under 1080p, then upscaled if necessary. Therefore 1080p anime didn't offer and advantages compared to 720p releases. I wonder if this is still true to this day.
Before that, I was usually impressed by Ufotables quality (Garden of sinners, Fate Stay / Night stuff).
Anime is computer edited 2D cells drawn on tablets for foreground and background and layered. The 3D work is limited to certain scenes.
3D animation can be scaled up and down, but it's not hand drawn and converted to raster images like the 2D cells necessarily.
I imagine with anime they just agree on a resolution for all the rasters and plug away at it, because they're under insane time/budget pressure.
The painted backgrounds who knows.
Maybe a better way of phrasing my answer is that Arcane was done in vector shapes.
Whilst anime is sometimes done "quick and dirty" by agreeing on a raster resolution and mastering everything in raster.