Venus has extreme heat and pressure at its surface. The temperature is around 500C, and the pressure is nearly 100 Bar (about the pressure at 3000ft depth). That is indeed hellish, and this is indeed a good question.
Depends on your definition of hellish. I guess Venus could be called that but it is not comparable to the pressures and temperatures that are found inside gas giants. For example Jupiter is estimated at 24000 Celsius at the core with pressures of several million bar. This is vastly different than environment on Venus and that is why they have no credible abiotic explanation for phosphine generation on Venus.
My point was that Venus is not comparable to a gas giant.
