Can a router kill network cards in 0.5-.15 years? Why does the router download slowly from some sites and quickly from some?

Question

Iron

A friend's router often breaks network cards. He slowly downloads files:
From Google drive Yandex disk. Mega and torrents download normally fast (5 mb)
C lcgenericname02.lc and steam installer download slowly (5-10 kb/s)
But when using a router in AP mode everything flies fine.
Router rt-g32. The processor heats up to 60-70 degrees (measured with a finger)

Answer 1

Pickups from the mains, shorting the wire, shorting the socket in the router, inconsistency with the mtu, broken network card, crooked drivers for it ... I'm guessing with a FINGER in the sky