Hardware decoders have memory limits and can't render SSA subtitles, which were designed by an insane person and require emulation of quirks of the Win32 font APIs plus a custom buggy implementation of 3D text rendering. (As far as I know, there are only three implementations and I wrote one of them.)

But also, Crunchyroll uses the fansub toolset and SSA subtitles.

The quality of fansubbing varies greatly depending on the translator too. For example, Crunchyroll uses ASS format for their own subtitles (things licensed from other studios seems to use a simpler format), and some translators do a really good job very similar to the fansubbers.

Case in point, I remember watching "Is the Order a Rabbit S3" in Crunchyroll, the English subtitles are pretty basic but the Portuguese (Brazillian) subtitles are great, including things like Karaoke in opening and ending.

> Fansubbers work for the shows they love while the commercial distributors just pick the cheapest option to get the thing done ASAP, don't matter how sh*tty the result is. There is no chance for quality here.

I wouldn’t call subtitles that require about a GB of RAM to process and don’t even get 20fps on an i7-6700 "quality". That’s just a bunch of shitty hacks people accept because there’s no alternative.

ASS is a horrible format (three implementations, only a single well-working implementation, performance hungry, etc), and almost all of the benefits of ASS can also be had with e.g. TTML without the issues.

And stuff like rendering the same line hundreds of times to get a gradient effect or blurred background is absolutely wasteful, especially because it’s just a hack to work around the broken ASS limitations.