[FFmpeg-user] Why FFmpeg provides it's own decoder, but relies on 3rd party encoders?

[Alexey Eromenko]

The important encoders I use myself are libmp3lame, libvpx, libx264,
libx265 and more...

Except for AAC audio codec, everything else uses 3rd party encoders,
but decoders for ffmpeg are built-in, right ?

Why so ? Because encoders improve faster than decoders ? Or because
encoders are more buggy, so you prefer to update them more frequently
?

Just wanna know a bit of background about political and/or technical
design decision of times past.

-- 
-Alexey Eromenko "Technologov"