It strains belief that anyone working on a moderate to large project would not have hit the edge cases and issues. Every other day I discover and have to fix a bug that was introduced by Claude/Codex previously (something implement just slightly incorrect or with just a slightly wrong expectation).
Every engineer I know working "mid-to-hard" problems (FANG and FANG adjacent) has broken every LLM including Opus 4.6, Gemini 3 Pro, and GPT-5.2-Codex on routine tasks. Granted the models have a very high success rate nowadays but they fail in strange ways and if you're well versed in your domain, these are easy to spot.
Granted I guess if you're just saying "build this" and using "it runs and looks fine" as the benchmark then OK.
All this is not to say Opus 4.5/6 are bad, not by a long shot, but your statement is difficult to parse as someone who's been coding a very long time and uses these agents daily. They're awesome but myopic.