Since LLMs have no internal evaluation, as a reviewer one has to account for it and evaluate line by line, rebuild from scratch any hidden rationale and tacit knowledge the LLM didn't have in the first place - only to be mislead into non concerns draining costly hours.
At this point, the investment is often deeper than writing from scratch.
But also, yeah, it starts to get worse than classic legacy code because you could try to build a theory of mind about the legacy code author(s). There were skills in trying to "mind read" a past generation. To find clues in poetry words more than the poetry form. (The variable names and whatever comments may have survived including commit logs; things written for humans to help explain the whys/hows, not just the whats.)
Came here to say this, but you said it for me. When you are an infinite code generator and your only parlour trick, your only hammer, is generation, and every nail is a problem of as-yet-insufficient generation, then generate you shall.
But the cognitive burden of metabolising this ultra-verbose, circuitous, often brute-force excreta is quite a bit higher than thumbing through a (competent) human's relatively terse approach.
Maybe companies today are being sold junk AI, and next step is being promised “solutions”.. capitalism is working exactly as expected
An additional factor: to find issues in generated code, the developer has to care. Many developers (especially at big firms) are already profoundly checked out from their work and are just looking for a way to close their tickets and pass the buck with the minimum possible effort. Those developers - even the capable ones - aren't going to put in the effort to understand their generated code well enough to find issues that the agents missed. Especially during the current AI-driven speed mania.