It has little to do with gullibility and more to do with the way they do things.

In principle AI Agents are superhuman at codeforces but tons of these vibe coded apps have ridiculously stupid performance problems.

The problem is a utilization of expertise thing, it can tell you with incredible detail about pros and cons and caveats to a problem if you ask about it. Truly superhumanly intelligent.

Calibration when it comes to actual decision making takes an incredible reduction in capability after that. Maybe it has something to do with the sycophancy or something but its like someone with exactly zero opinions (and therefore, taste).

My experience is that you can brainstorm with it on "Do A or B?" and it will produce a coinflip answer A, then if you continue and ask about a specific concern "what about this aspect of B?", it immediately 180s and flips back to B being way better than A.

Acting on this expertise when decision making points arise naturally for itself is where everything really nosedives. It's just gonna do whatever.

So when you are doing this "financial advice please" questioning, it is entirely hitting these weaknesses squarely in the face.