No, the tradeoff is actually the other way around. Encoding with a neural network can potentially be faster than the exhaustive tree searches that are done in current compression methods. On other hand, current decoders are fairly dumb and extremely optimized for speed. Neural networks will probably have trouble competing. In the design of video codecsan increase in decoding time is considered at least 10x more costly than the same increase in encoding time.
source: I worked with both HEVC and neural network based compression.
source: I worked with both HEVC and neural network based compression.