HTupolev

The use of pulleys does not in and of itself facilitate cog-tracking. Rear derailleurs may employ a jockey offset or b-pivot rotation, but these aspects exist in part to circumvent challenges created by the pulley's role in chain tensioning. Some modern rear derailleurs employ neither of these, like the newer Shadow rear derailleurs intended for multi-ring setups in Shimano's road and gravel lineups: whether it's a Di2 Dura Ace RD-R9250 or a mechanical GRX RD-RX810, the position of the jockey pulley purely follows the round curve defined by the parallelogram.

And while pushing a chain with plates is very simple, I wouldn't call it "crude." It's the reasonable way to do it anywhere in a system that a derailleur isn't also operating as a tensioner.
The main impediments to front derailleur performance are the fact that derailments are initiated on the part of the chain that transmits pedaling forces, and the huge sizes of the shifts that we ask front derailleurs to make. And it's mostly the latter: front derailleurs can be very quick and butter-smooth when the shifts are in the 10T range or smaller, and what this means for shifts between middle and big rings of many triples is one of the main things I like about using triples.

It's also why I think it's silly that interleaved gearing hasn't been brought back. A front shift of just a few teeth could be made extremely snappy and smooth with modern shift gates. Synchro would eliminate the human aspect of double-shifting. With just a 2x11 you could have a gearing range of >500% with all gearing steps in the 7-11% range.