The Raspberry Pi Foundation seems deadset on pushing the same genre of chip from Broadcom forward. I doubt the serious bandwidth limitations (all your I/O going over 1 USB port) or the notable chipset flaws (1GB of ram max) will be amended any time soon. They've had 6 years to fix the Raspberry Pi, yet it still has the same hard limits.
IDK I'm hoping the RPI4 will arrive when 4K starts become more prevalent and can do the HVEC decoding
HEVC on the next generation of Raspberry Pi is highly unlikely due to both licensing costs and Broadcom not having a cheap IP block to use for adding HEVC. 4K is more likely, but if you want that today go get an OrangePi for less than the cost of a Raspberry Pi. It even has HEVC 8bit support!
What online service is giving you 480mbps or better?
haha thats theoretical. Real world is 2-3MB/s over lan. Also Ethernet is 100mbit
This sounds an order of magnitude lower than RPi 3 B+ published network performance benchmarks, you should get around 250 Mbit/s = 30+ MBytes/s. Also, it's gigabit ethernet now.