Wireless vs Ethernet, does Ethernet have less ping?

Ping is an imcp request to test connectivity. But to answer your question, yes, you will get better speeds off a wired connection than a wireless one. It's just a lot easier to send electric pulses through a wire than the air. Try wikipediaing CSMA/CA vs CSMA/CD

Wired is also more reliable. Wireless signal can be easily degraded by walls, other signal interference and having a weak signal from being to far away from neighboring wireless points.

Although older wired cable can get slower the longer the length of cable, newer revisions alleviate this problem with increased technology, and make it unlikely you will not any speed degradation in a typical home wired network. To degrade and/or break a wired signal physically, you would need to either cut the cable to damage some of the wires by cutting through the protective outside shielding.

Wired is generally better but comes at the cost of messy cables if not managed correctly.
Wireless is more convenient but suffers slightly in performance and reliability.