wasn't some of that smoothness because it ran at a 100hz tick without any way of adapting it (and still running existing code)? That was the complaint I kept hearing from people attempting to make flash on phones viable (this led to ludicrous battery consumption)

It could be smooth AF in ways that a video on a service like YouTube never could be.

I didn't get into flash games at all, but I used to watch Flash animations.

Like, for instance, Salad Fingers: https://archive.org/details/flash_salad-fingers

This was intended for a slow 2004-era computer with a 4x3 (probably 1024x768) display, where it worked very well.

But it's not 2004 anymore; things are much faster and screens have gotten a lot bigger. Here in 2026, Salad Fingers renders out fine at higher resolutions, and at different aspect ratios. It works great on my desktop at 1080p, without stretching [and with some probably-unintentional extra content on the sides]. It even works on my pocket supercomputer's 3200x1440 20:9 display.

Vectors are fun, and they scale as technology improves. The lines remain smooth and defined. And with Flash, that's a built-in: An unaltered 22-year-old digital animation still looks crisp.

For contrast, if Salad Fingers had been published on YouTube way back around that time, it would have been in chonky fixed-pixel 320x240. Maybe that would be as good as it would ever get unless it were rendered and uploaded at higher resolutions later.

Image-wise, SVGA + JS probably gets you the clarity. Standard gif / image animations not so much, if that's what you're referencing.

This isn't my baliwick, so I've absolutely nothing to say about the ease with which these options can be created.