Dont underestimate complexity. For android you have to ship basically ffmpeg for correct mp4 encoding, on all platforms you have to carry some library on top o

Dont underestimate complexity. For android you have to ship basically ffmpeg for correct mp4 encoding, on all platforms you have to carry some library on top of classical ui framework to make it just not suck at performance, you have to get your own json parser, yes, since built-in one will be 10x slower, you may be want to carry even low level QUIC library for networking and websockets, etc, etc. All this also not increasing complexity since built in one stuff makes your code much harder to read/write.