Fiber is OK if you have devices that support it, but if not, that means converters and more expense. Cat.6e is not going anywhere anytime soon. Cat.5e isn't obsolete yet despite being over 20 years old.
My general advice about WiFi is: avoid it if you can until the channel / spectrum situation gets a total overhaul. If a device supports cabled Ethernet, give it Ethernet. This is especially true for high-bandwidth applications such as 4K video to TVs.