Various arguments for wiring your home with Cat 6 (gigabit) ethernet or better.
Bottom-line advantages of Cat 6 over 802.11ac WiFi:
- Better capacity. While 802.11ac, under optimal conditions, can approach 500 Mbps, having a wired connection that guarantees 1000 Mbps can be useful.
- Better reliability.
- Better security.
- Better latency.
All of this said, it isn't either-or -- you can use your wired connections for connecting computers to NAS or when you need maximum speed for uploading.
- At some point, you might consider a NAS (Network Attached Storage) for your home, like a Synology NAS. These make it convenient to store lots of media. Having fast transfer rates to your NAS is a big help; the best way to get that is via a wired connection.