Front shifts are inherently less rapid because the distance the derailleur must move is greater. Whether the big jumps were up front or in the back, so long as the two- (or three-) chain ring design in used, one derailleur is going to have to move the chain a relatively larger distance.
I am not sure how a bike could be designed so that the front derailleur would shift a lightly-loaded chain .... there is not enough space up front (ahead of the chain rings, between the chain and tire) or under the BB for a jockey-wheel arrangement (safely (as I see it)) and frankly ....I don't see the need.
Modern derailleurs are amazing compared to what we had a few decades ago .... and they worked well enough back then. Perfect? Nothing is. Useful? No front derailleur has even stopped me from riding.