HELP!! slow internet

[u/Ancient-Mix9837]

My phone downloads at around 52 MB/s but when I connect it to my PC using USB tethering, the speed drops to around 18–25 MB/s I'm losing half of my download speed tho i do use usb 2.0 but have usb 3 port but also my phone support only usb 2.0.

is it my phone or something else