Getting a usable PRD is often the bottleneck.

You forgot to add "coordination" to that pipeline. That is easily far and away the biggest source of delays.

That includes talking to vendors, meetings with every layer of stakeholder when just one person digs their heels, etc.

That is truly the final frontier for "AI", and one that it will likely never cross. That would be when even the execs and upper management feel threatened by "AI". But, since they also delegate so much, you often see someone at the bottom of the totem pole in those meetings. This is why nobody is getting replaced by "AI". We really need to move this discussion away from the scifi stupidity already. There is no singularity or godlike AGI about to take over the world.

I hate to use awful terms like "synergy" and "teamwork", but they do have a lot more substance and truth to them than any perceived threat from "AI".