USB 3.2 Gen 2x2 handling 4k @ 144hz. How?

I have a maybe silly question. I have a 4k 144hz monitor (Gigabyte M28U) and I am using it as an external monitor for my laptop (Alienware x15 r2) which has a thunderbolt 4 port.

A quick google search informed me that 4k @ 144hz would require approximately 35Gbps bandwidth. As I understand, a USB 3.2 gen 2x2 cable has a maximum bandwidth of 20 Gbps.

Here's my question: The cable I tested this with is a USB 3.2 Gen 2x2 from amazon, and yet I was able to set my monitor to 4k resolution and 144 hz framerate - how is this possible? Is my understanding of bandwidth and cable specs incorrect?

I really just want to know if I actually need to buy a USB4/TB cable or if I can just keep using this one I already have. Thank you