Big stage shows use line arrays, usually just one set to each side of the stage, but occasionally you see a set of delay towers as well if the venue is deep enough. You don't need complicated controllers built into every cabinet to deal with that effectively. Delays and EQs can be set in the console, which is all digital. Anyway modern amps can fit 10kW of amplification plus DSP plus network control into 2RU, and it just doesn't make sense to spread 6RU of equipment out into 16 cabinets of a reasonably sized array. Plus you'd have to run power+signal to every single cabinet, and you'd have three times as many devices to manage and configure, and once the array is hoisted you can't get to the cabinets, so what would you do if one of the fancy in-cab controllers goes insane ten minutes before doors?
And yes, audio over IP is already standard. Massive multi-channel snakes with dozens of copper lines are gone, you plug your mixing console into the show network, and it talks DANTE to your stage boxes through a fiber backbone. A Cisco cert is a legitimately marketable qualification for the modern stagehand (although now there are several lines of networking infrastructure gear purpose-built for production usage, so standard enterprise networking gear is becoming less common).