What is the most used USDT network?

Could you please enlighten me on the most popular USDT network currently? I'm quite curious about the ins and outs of this digital currency, especially its network usage patterns. I've heard USDT mentioned often in financial discussions, but I'm still a bit hazy on which network it predominantly operates on. Is it Ethereum? Or maybe Tron? Or is there another network that has gained significant traction? Could you also provide some insights into why this particular network is so widely used? I'm interested in understanding the underlying reasons for its popularity, such as transaction speed, cost-efficiency, or compatibility with other blockchains. Thank you for your time and expertise.