That was just a quote, anyway I asked anonchatgpt.com and it says both play a role:

The Venusian surface experiences extreme temperatures due to a combination of several factors. The main reasons for its high temperatures are:

Runaway Greenhouse Effect: Venus has an extremely dense atmosphere mostly composed of carbon dioxide (about 96%). This thick atmosphere traps solar radiation and creates a greenhouse effect, much stronger than on Earth. This process causes the surface temperature of Venus to rise excessively.

Atmospheric Pressure: Venus also has an incredibly high atmospheric pressure, about 92 times that of Earth. The weight of the dense atmosphere compounds the greenhouse effect by trapping even more heat, further increasing the surface temperature.

Absence of Water: Unlike Earth, Venus has very little water vapor in its atmosphere as it underwent a process known as a "runaway greenhouse effect" early in its history. Water vapor is an efficient heat absorber and can help regulate temperatures on planets. With little water vapor, Venus lacks this natural temperature regulation, resulting in higher surface temperatures.

Lack of Oceans: Venus has a dry and rocky surface with no significant bodies of water. Water bodies on Earth help to absorb and distribute heat, acting as a temperature buffer. Without the presence of oceans, Venus doesn't have this mechanism to regulate its surface temperatures.

Combining these factors leads to the scorching and inhospitable surface temperatures on Venus, averaging around 900 degrees Fahrenheit (475 degrees Celsius), making it the hottest planet in our solar system.