Partially. There are local (L2) and fast re-transmit with ARQ [1] and HARQ [2] (at least in cellular, which I know, but I guess Wifi likely has both too), and i

Partially. There are local (L2) and fast re-transmit with ARQ [1] and HARQ [2] (at least in cellular, which I know, but I guess Wifi likely has both too), and it can help hide some packet loss to the upper layers. But this still creates added delay, which is seen by TCP as more RTT jitter, with a bad impact on performance. Also, if the link degrades really badly TCP will definitely see more congestion and loss. So yes, the L2 will do all it can do hides wireless issues to the upper layers. But it cannot make miracles and wireless is still a challenging medium for end-to-end congestion control. There's still work at the TCP (or let's say end-to-end congestion control layer, with QUIC) to improve things, see BBRv2 for example. It's an active area, and any new generation tends to push the current state of the art. [1] https://en.wikipedia.org/wiki/Automatic_repeat_request https://en.wikipedia.org/wiki/Automatic_repeat_request [2] https://en.wikipedia.org/wiki/Hybrid_automatic_repeat_request https://en.wikipedia.org/wiki/Hybrid_automatic_repeat_reques...