Think of it as a layered problem. If the bottom layer (CI) cannot keep up with the output of agents, then solving problems at a higher layer - like user experience checks - will be exponentially slower and less reliable. Kind of like how optimizing tight inner loops makes your whole program faster.
Clearly you have to replace obsolete human testers with agentic AI testers, duh.
At some point, with all this velocity, human users become the bottleneck, unable to keep up with and learn all the changes and new features. Luckily, there's a simple solution: just replace the human users with agentic AI users.