Question is, why would anyone want a wireless connection...?
They don't..! Wireless is just a personal compromise, to make something "easier", or cheaper for someone. Why even build a quality or performance orientated computer, and use wireless internet?
100ft of cat6 is pretty cheap.
I can't start drilling through the walls of my rented apartment to run cables from the router to my computer. I'd get evicted.
802.11ac provides me with about 550 Mb/s actual throughput, which is enough for my needs. I only have a 250 Mb/s Internet connection. Even transfers to/from my wired NAS are good enough - 60-65MB/s with SMB.
For my desktop I use an Asus PCE-AC68 with a big external antenna. I doubt any of those built-in wireless solutions would provide good performance. However for a HTPC just streaming video for example, it would probably still be enough.